Trinity – Simply: These three are one

has no analogy in human beings or relations, as Hilary of Poitiers argued. This conclusion returns the doctrine of the Trinity to its basic meaning within the discourse on God. It has its own stance, and it should not be burdened by speculations on desired human relations. Intradisciplinary and/or interdisciplinary implications: For the discipline of systematic theology the conclusion of this paper implies that the doctrine of the Trinity should not be mirrored in theological anthropology but should be restricted to the discourse on God. This will challenge theological anthropology to be developed from another perspective, with a clearer distinction of Creator and creation.


Introduction
The Trinity is a core theme in recent theology. This has been said frequently, and telling this again is belabouring an obvious point. However, what the Trinity means is not as clear as that. The model of a social Trinity has been dominant in leading theological circles for several decades. Especially, Moltmann (1980) and Catherine LaCugna (1991) promoted it (see also Rohr 2016). However, other models were developed simultaneously, such as the Trinity as an expression of God's involvement in history (Berkhof 1973;Jenson 1997), designs which plead for focus on unity rather than on communion and the relation of the persons and explicitly oppose the idea of a social Trinity (Sonderegger 2020;Wisse 2011) or expression of the diverse aspects of the mystic union with God (Marmion & Van Nieuwenhove 2011). Bracken elaborates the concept of a social Trinity as a key for understanding not only human relations but for the whole universe (Bracken 2001). This article focuses on the social Trinity, but the conclusions can also be applied as a response to other modern Trinitarian designs.
Most trinitarian theologians call on texts of the patristic period for developing their argument. That is especially the case for those who promote the idea of a social Trinity. This paper will analyse these references and critically assess these, subsequently revisit positions of early Christian writers on the Trinity and finally draw a conclusion to a valid and basic doctrine of the Trinity.

The social Trinity
The idea of a social Trinity is inextricably linked to Jürgen Moltmann. In his book Der gekreuzigte Gott (Moltmann 1981), he argues that God is an event, wherein the Father and the Son are involved in the salvation of the world. The Father gives the Son, and the Son obeys the Father on the cross. It could seem that this is actually not about the Trinity but about Binity, like many trinitarian designs, both in the early church and today. If it were only about Der gekreuzigte Gott, this might be true, but that Trinity has been one of the core topics of theology during the last half century. Especially, the idea of a social Trinity has been promoted by leading theologians. This interpretation of the Trinity is often related to the theology of the Cappadocian fathers at the end of the 4th century, in contrast to the individualistic trinitarian discourse of Augustine, the father of Western theology. It appears that this theory is an untenable construct. The first leading theologian who developed the concept of the social Trinity, Jürgen Moltmann, did not relate it to the Cappadocians but to Augustine. It was especially John Zizioulas who promoted Cappadocian trinitarian theology as a base for social relations. By doing so, he not only neglected the social interpretation of Augustine by Moltmann but also disregarded the fundamentally apophatic character of Cappadocian theology. The discourse of the Cappadocians is about the way God is different from human beings, and its focus is not on relations of persons but about mutual indwelling of divine expressions of being. A social Trinity could rather be related to the African Tertullian. However, finally, the Trinity is not more than a formula for telling that the Father, the Son and the Spirit are real persons, and really one, as well. It is a formula of God talk, which serves worship and Christian life, and has no analogy in human beings or relations, as Hilary of Poitiers argued. This conclusion returns the doctrine of the Trinity to its basic meaning within the discourse on God. It has its own stance, and it should not be burdened by speculations on desired human relations. book was soon followed by Kirche in der Kraft des Heiligen Geistes (Moltmann 1975). From this publication, it is clear that according to Moltmann, God's presence is not limited to the event of the crucifixion but continues in the church. So both books together develop a full trinitarian theology. The impact of the confession of God being a Trinity is further elaborated by Moltmann in his subsequent book Trinität und Reich Gottes (1980). The Trinity is not a topic that is interesting for the inner circle of the church, but it clarifies the whole creation and opens the future of all being. Moltmann's later books, for example, on creation (Moltmann 1985) and on the Holy Spirit (Moltmann 1991) can be seen as elaborations of this basic theological position.
Moltmann's theology has strong biblical roots. His trinitarian approach is not developed from traditional discourses on the Trinity but arises from dealing with texts of the Gospels about the events of Jesus' last day, the day when he was crucified, especially with texts with conversations of the Father and the Son. Moltmann has no hesitation to call the Son God. This gives tension to his analyses of the conversations of the Father and the Son, which challenge theology. These are real conversations in God, with tensions as in any conversation which matters. God's divine Being is not an immovable, imperturbable unity of the Absolute but an emotional event of deep involvement, as love finds its identity in action. 'Mit «Gott» ist ein «Geschehen» gemeint: das Golgathageschehen, das Geschehen der Liebe des Sohnes und des Schmerzens des Vaters, aus dem der zukunftseröffende, lebenschaffende Geist entspringt' (Moltmann 1981:234).
The challenge of Moltmann's discourse on God as an event is brought to the maximum because he adopts Barth's thesis that God is only known by his self-revelation (Barth 1981:313;Moltmann 1980:154-161) and consequently that the economic Trinity is the only access to the essential Trinity. God is not only an event in the perspective of his acting in history but also in his eternal Being. This divine Being is totally different from the Aristotelian Unmoved Mover, rather the opposite: a dramatic event of ultimate relational love.

Between East and West
It is necessary to stress these roots of Moltmann's theology of the Trinity, because the idea of a social Trinity is often related to the Cappadocian theologians of the 4th century (e.g. Constas 2006;Schwöbel 2014:27;Volf 2006:6) usually in contrast with Augustine's design that he developed in his On the Trinity. In the discourse that arises from these connections, soon trinitarian concepts and their interpretations become dominant on a high level of abstract theology. This is far away from Moltmann's dynamic, vivid discourse in The crucified God.
It is not Moltmann who related the social Trinity to the Cappadocians. And it is not Moltmann who placed this in opposition to the theology of Augustine. In Der gekreuzigte Gott, he does not mention the Cappadocians, and even in Trinität und Reich Gottes he only once mentions Gregory of Nazianza (Moltmann 1980:216). The link between Moltmann and the Cappadocians that Constas (2006) claims is his own construct, not the result of Mioltmann's own references.
It is rather Augustine who is Moltmann's witness in church history for supporting his idea of a social Trinity: God is Triune as love, in the mutual relation of Lover and Beloved (Moltmann 1980:73;Augustine, De Trinitate VI,5.7). It is Augustine who, according to Moltmann (1980:188), introduced the relational interpretation of 'person'. It is this basic idea of Augustine on the Trinity, from which the filioque arises, that Moltmann embraces: the loving Father, the beloved Son and the Holy Spirit as their mutual bond of Love. This 'mutual' is the base of the filioque. Moltmann relates his theology on the Trinity to the basic expression of it by Augustine, which has been adapted by the Western tradition, not only by authors such as Richard of St. Victor (Angelici 2011) but also by theologians such as John Calvin, who are more reluctant to introduce social relations in the Trinity and play down the language on persons.
The foundation of the idea of a social Trinity in the theology of the Cappadocians does not come from Moltmann and also not from LaCugna, who has also been very influential for the propagation of the concept. She stressed, in contrast to Moltmann, the opposition of the concept of the social Trinity to Augustine's ideas (LaCugna 1991:81-104). She did not focus on the social aspects of Augustine's theology of the Trinity with mutual love as a core concept as Moltmann did but on the psychological interpretation of it, which Augustine developed in his earlier book On the Trinity. LaCugna contrasts this to earlier expositions of the theology of Trinity in the pre-Nicaean period and concludes that Augustine introduces a new model that has been of great impact in the development of Western individualism. Although this is different from the model of the Cappadocians, LaCugna does not promote the latter, but she blames the Cappadocians for developing an abstract doctrine of the Trinity by separating theologia from oikonomia (LaCugna 1991:9, 53-73).
The connection of the Cappadocians with the social Trinity, in contrast to Western theology, must rather be ascribed to the influence of Zizioulas, who, living and working in the tradition of the Eastern churches and well acquainted with the Cappadocian theologians, elaborated their theology of the Trinity in the perspective of a social Trinity (see Zizioulas 1995Zizioulas , 1997Zizioulas , 2006. The theology of the Cappadocians starts with the persons but is developed as a discussion about their relations. Because the persons are related, a relational theology seems self-evident. It is from this starting point that Zizioulas elaborates his trinitarian theology as a critique of Western individualism. The ground of being is not the absolute One but a social community of equal persons. 'It is the other and our relationship with him that gives us our identity, our otherness, making us "who we are", that is persons' (Zizioulas 2006:166).
This theology corresponded well with the interests of Western theologians who were tired of individualism. Introduced by Zizioulas, a new way was opened to them in the sources of the tradition of the church, with new perspectives they were longing for. And so the Cappadocians became the fathers of hope, in opposition to Western individualism.
[I]f we are allowed or even incited in our culture to think or hope for true personhood in human existence, we owe it above all to The father of Western theology is Augustine, so he was created as the main opponent of the Cappadocians. It is remarkable that LaCugna (1991:9, 53-73) appreciates Zizioulas' position but does not refer to him in her interpretation of the Cappadocians.

Augustine revisited
Many recent authors chose the side of the Cappadocians, but some take the side of Augustine, such as Maarten Wisse, who exposes a strong plea on the defence of Augustine (Wisse 2011). However, the opposition is maintained. Kärkkäinen (2014:278) rightly argues that the opposition is based on an unfair interpretation of Augustine. Marmion and Van Nieuwenhove (2011:82-95) take a different tack. They argue that Augustine is not so individualistic as the adherents of a social Trinity claim. They point to the later books of Augustine where the outcome of his whole trajectory leads to mutual love, as the end of a spiritual journey to the loving God. 'He sees the highest human trinity not in the human mind remembering, understanding, and loving itself, but in remembering, understanding, and loving God' (Marmion & Van Nieuwenhove 2011:91). The human involvement in the Trinity is not individualistic but relational, with love as the core of relation and the love to God and from God as its apex, not in contrast to human social relations but as its base, for Christian life is faith that works by love (Augustine, De fide, spe et caritate 8, citing from Gl 5:6).
[I]ntegrating the concept of love in his theology, particularly his theology of the Spirit, [Augustine] laid the foundations for a spirituality based on a trinitarian rhythm of giving and receiving love. (Marmion & Van Nieuwenhove 2011:92) The influence of this spiritual, mystical approach of Augustine can be traced in the whole Western tradition. The opponents of Augustine's theology of the Trinity are, according to Marmion and Van Nieuwenhove, fighting against a caricature.
Augustine's On the Trinity is more nuanced, indeed, than a simple opposition of social and individualistic suggests. It is not only the reference to love as the core of the Trinity but also the exposition in psychological terms that can be interpreted in a relational way. It displays the way whereby a human being grows into the communion with God. It can be interpreted as an elaboration of the famous Augustinian adage: 'Our heart is restless until it rests in you' (Augustine, Confessions I,1,1). The way to human destination is the process of accepting creation, becoming saved and entering into a reconciled life of ultimate love, finding rest in a love so old and so new. It is the experience of the deepest love, the mystery of Love itself as the mystery of the eternally loving God. This mystical interpretation of Augustine is just as much contrasted to individualism as the idea of social Trinity. It is ultimate love and ultimate relation, so ultimate that the other one defines my identity. From this perspective, one could even blame the adherents of a social Trinity that they have a poor concept of love: asking for personal relations instead of totally being for and in the other one.
Because Augustine's theology on the Trinity is related to the filioque, it is necessary to pay some more attention to this concept. The filioque has complex notions. The first notion is the mutual love of Father and Son. Subsequently, human beings are involved in this love, wherein they find their destination, and, then, this love works in mutual love of human beings.
However, it can also be interpreted as an ongoing movement enclosed in the divine being: from the Father to the Son and from the Son to the Father. An outward movement is not necessary. The divine love of the Father and the Son is perfect in itself. So the filioque can be interpreted as the ultimate individualism of eternal self-love (see Du Roy 1966:463). In contrast, the movement of the Eastern theology is from the Father through the Son as an eternal outgoing process along the celestial and earthly hierarchies. Consequently, the West has problems finding connections of the divine and human, for example, in soteriology (how do I participate in Christ?), while the East struggles with distinctions and the temporality of created beings.

The Cappadocians
It appears that the concept of a social Trinity was developed in a discussion with Augustine. For both Moltmann and LaCugna, he is the main partner in debate, for Moltmann as a positive reference and for LaCugna as contrast. From Moltmann's theological development, it may be clear that the plea for a social Trinity is not derived from the theology of the Cappadocians but has its own sources and dynamics. Two decades before Moltmann's Trinität und Reich Gottes, Pannenberg already pleaded that person is relation (see especially Pannenberg 1961), and he derived this idea from the doctrine of the Trinity. Pannenberg does not hide his sympathy for Hegel (Pannenberg 1961:232), and it is rather Hegel's philosophy that was helpful for opposing Western individualism than the Greek fathers.
Nevertheless, the Cappadocians were introduced into the modern debate on the Trinity, especially by the works of Zizioulas. The theology of the Trinity of the Cappadocians seemed to support the social Trinity perfectly, so it was eagerly accepted by Western theologians who aimed to contest individualism. From the perspective of LaCugna's interpretation of Augustine, the Western doctrine of the Trinity was individualistic. This was contrasted with the Eastern exposition of the Trinity, where relations of the persons are basic. On the one hand, the persons are well defined in the social Trinity, even to such an extent that Moltmann was blamed for tritheism (Marmion & Van Nieuwenhove 2011:17-18 It is a misunderstanding of Moltmann to blame him for tritheism, because God is not the sum of three individuals who subsequently interact, but the interaction itself is the divine Being. God is an event, the event of the Father who suffers because of the sufferings of the Son, with the power of the love wherein the Son gave his life, first to the Father, but through their Spirit, subsequently to humanity. It is this dynamic character of interaction of the persons that made the Cappadocian theology so attractive for Western theologians. Although the discourse is about the persons, it is the procession that makes the Trinity. Dynamics prevail over entities. This dynamic is not only the source of the persons but also defines their identity. The identities are defined by the other one (Gregory of Nazianza, Oratio 25.16; 29.16; Augustine, De Trinitate V,5.6, has the same argumentation): the Father is only Father because he is the Father of the Son, and the Son is only so as the Son of the Father, while the Holy Spirit is blown by the Father through the Son. Consequently, the three persons do not exist independently. They are always mutually related, and there exists an indwelling of the one in the other. This indwelling is explicitly exposed in the concept of perichoresis. This concept was initiated by the Cappadocian fathers and fully developed by John of Damascus (De fide orthodoxa I.8). No borders exist between the persons. Their being is not only derived from the identity of the other one, but it also penetrates the other persons. According to Gregory of Nyssa, this is not a partial indwelling. It is about their full being as shared life: [W]e consider that it is right to think that that which is joined to the Father and the Son in such sublime and exalted conceptions is not separated from them in any. … For all the Divine attributes, whether named or conceived, are of like rank one with another, in that they are not distinguishable in respect of the signification of their subject. (Gregory of Nyssa, Ad Eusthatium: De Trinitate 5; translation Wilson 1893; see also Bardenhewer 1923:157) The life of the Logos is not multiple or participated, or else it would lose its simplicity (Gregory of Nyssa, Catechismus maior 1). Origen (De Principiis I.2.6) already opposed the idea that the Son would be a part of God. And both Gregory and Origen relate this to the will. This is in opposition to Tertullian, who speaks frankly about the Son as a portion of the divine Being: 'For the Father is the entire substance, but the Son is a derivation and portion of the whole, as He Himself acknowledges: My Father is greater than I' (Jn 14:28; Tertullian, Adversus Praxeam 9; translation Holmes 1885b).
The theology of the Trinity of the Cappadocians is actually not so much about relations of persons but a theology of unity. It is the dynamic process of processions and perichoresis of identities which only exist in this process and can never be fixed as isolated entities. Basil uses the metaphor of a team for clarifying what the Trinity is (Basil, Epistola 210). This seems to direct the attention to the three and could be interpreted as almost or even full tritheism. However, the focus of Basil in this discourse is not on the three but on unity. The question is if three persons can be one -and this unity is found in their shared interest in the gospel. It is this shared interest which is the true metaphor of God, just as being one family is the shared identity of Adam, Eve and Seth (Gregory of Nazianza, Oratio 31,11). From the family metaphor, it may be immediately clear that it is not the persons who provide the material base for the comparison, for God is not man, wife and child. It is being one family with several faces which is compared with one God in three persons. The structure of the argument is: although God seems three, He is nevertheless one. The focus is on unity and the claim for unity is the core of the argument.
It must be wondered if this concept can be used for a plea for a social anthropology, as the theology of the social Trinity is applied by Western theologians. A social, relational anthropology presupposes human beings as defined entities who have relations and even cannot exist without relations. Although this relational character is basic, it does not deny the individual identity of the persons. They can even change their social networks -or participate in several networks synchronously. Mutual dependence and mutual relations of human beings, even as strong as possible, are different from processions and perichoresis in the doctrine of God. Randall Otto (2009) concludes that the concept of perichoresis is abused for human social theory and robbed of its true meaning. He explicitly mentions Jürgen Moltmann as a theologian who does not use the concept correctly. It is developed for a discourse on God and exposes what is only true for God, different from any human relations. Processions and perichoresis are concepts of theology in the strict sense. They cannot and may not be used for anthropology, not even for a theological anthropology. They display the otherness of God, precisely in order to indicate that the divine persons are different from human persons, who may have wonderful relations but who do not have perichoresis into each other. Not contributing perichoresis to human beings is even the base of human freedom. Humanity is not a unity as the triune God is.

Apophatic theology
The modern use of the theology of the Cappadocians for the social Trinity, such as Zizioulas (1995:46), who explicitly relates the Trinity to the revelation of God's very being, does not correspond with the fundamental apophatic character of Cappadocian theology. We cannot grasp the essential being of God, precisely because God is different from human beings. Concepts like procession and perichoresis are introduced in order to secure this difference. Human beings do not come into being by procession. Their relations and personhood are not defined by perichoresis. The movement of the arguments of the Cappadocians is to the mystery of God, which cannot be grasped by any human being, not even by analogy. Analogy is a Western concept, corresponding with cataphatic theology, trying to define what is identical within the limits of essential difference. Eastern apophatic language prefers keeping to the 'is not'.
This does not mean that Eastern theology is fully apophatic. If apophatic speech is pushed to its very end, nothing is left in language about God. With regard to this, there is an interesting sentence in the paragraph on the Trinity in De fide orthodoxa of John of Damascus. He writes that God is 'a power known by no measure, measurable only by His own will alone' (John of Damascus, De fide orthodoxa I,8; translation Watson & Pullan 1899). So God is, according to John of Damascus, not at random infinite. It is his will which defines his being. Origen already relates the Trinity to the will of God (De principiis I.2.6; I.2.9; IV.4; see Van de Beek 1998). Jesus is the Son of God's will. 'Love' in the relation of the Father and the Son is interpreted by Origen as 'will'. It is often argued that Being is the core category of Greek theology. However, this being is defined by Will as the essential category for thinking about God. And the will of God is not undefined. It is expressed in his acting. This does not imply that Eastern theology of the Trinity would immediately run with Rahner (1967:328, see also 327-329, 352, 382-383) and Barth that the essential Trinity is identical with the economic Trinity, and the oikonomia of salvation is the essential being of God. God's acting is more than salvation. His eternal Will is allcomprehensive. Anything that is and anything that happens is the result of God's will and acting. We cannot grasp all the ins and outs of what is. We cannot fully understand history. Even less we can grasp celestial spheres. But we know that all this is the result of an ultimate Will, who defines his own Being and the being of all what is not himself.
Dionysius the Areopagite has designed a hierarchy of all beings, celestial and earthly (Dionysius Areopagita, The heavenly hierarchies; translation Parker 2021a; Ecclesiastical hierarchy, translation Parker 2021b). The divine hierarchy is expressed on Earth as ecclesiastic hierarchy. If there is a similarity with heaven, it is not in humanity as such but in the hierarchy of the church, where a will, which is unfathomable, defines what the church is and will be, a will on whom all people are dependent. The hierarchy of priest, bishops, archbishops, metropolitans and patriarchs comes down from the celestial hierarchy, and nobody can grasp the decisions and ways in which they operate. They are related to the whole creation, which is expressed by the political hierarchy with a will at the apex of earthly dominion, which is the privilege of the emperor, a will that is intrinsically related to the hierarchy of the church. How these interrelations run will never be clear for common human beings. Processes between church and state move, and move on, in a unity on which all people depend. They are expressions of Will, but a Will that cannot be grasped. The unity of nation and church is a mystery, as expression of the mystery of God that exceeds all wills on Earth and defines all mysteries of the world.
Platonic philosophy, with its hierarchical structure, is the backdrop of Eastern theology rather than modern Western social and social psychological discourses. Eastern orthodoxy is a different world from Western thought and Western critical sociology. It is more reflected in Eastern European societies such as Russia and Serbia than in Western social longings. Undefined unity with hierarchic will as its centre is decisive for Eastern theology as it has been developed, as the leading theologians of the end of the 4th century had to answer the challenges of a Christian empire with the claims of Byzantine emperors.

Earlier trinitarian theologians
The trinitarian theology of the Cappadocian fathers cannot be used for modern discourses about social relations. If a reference in early Christianity might be sought, it is better to look to the North African Tertullian or the Gallic Hilary of Poitiers. The focus of the Cappadocians was on unity. They grew up in the 4th century, when the impact of the council of Nicaea shaped orthodox theology (LaCugna 1991, Part I, gives a sharp exposition about these developments). Nicaea stressed the divinity of the Son as never since Paul. Athanasius continued on this path and also added that the Holy Spirit is as divine as the Father and the Son, for only God can save us, and it is by his divine Presence only that we receive life. Athanasius says that those who reject the divinity of the Spirit can be compared with Arians who reject the divinity of the Son: 'Therefore it is not necessary to say anything more in reply to them' (Letters to Serapion I,2; Shapland 1951:61). 'Is it not blasphemy for you to say that the Spirit is a creature, in whom the Father, through the Word, perfects and renews all things?' (Letters to Serapion I,9;Shapland 1951:82). So the confession of God as the Father, the Son and the Holy Spirit was well established when Athanasius died and the Cappadocians succeeded him as leading theologians. The three persons were not a matter of debate. However, God's unity was challenged by this confession. The new generation had to explain how God is one, even more so because they had to develop a discourse which supported the unity of the empire and the unity of the church, which soon became a state church. With their focus on unity as the aim of their argument, they stressed the processions, and later perichoresis, in order to play down the distinctions between the persons, even to such an extent that the only distinctions that were left were the mutual dependencies of being Father and Son and the spiration of the Spirit.
Tertullian, about 200 AD, was in a different position. Unity was still the basic concept of God. A few decades earlier, Irenaeus of Lyon had already to answer the question how God, being one, undivided, could create a world. His answer is that he does so by the Word and the Spirit, as his hands (Irenaeus, Against heresies IV, Preface 4; V,6,1; V,28,4). But this still implies a unity of God as one person. Tertullian, with his paradoxical theology, stretches plurality further. He meditates on the concept of monarchy that his opponents push forward (Tertullian, Against Praxeas 3-4). If God is one, he is the source of all, and consequently, there is only one source, one archè. Two archai would support Marcionite heresy. God is the single, sole principle. The modalists, such as Praxeas, drew the conclusion that if God is revealed as the Father, the Son and the Holy Spirit, these three can only be phenomenal expressions, modi, of the same God. Tertullian starts with blaming them for a wrong concept of monarchy. Monarchy is not about one principle but about one rule. It is not the Greek philosophical concept for which Tertullian opts but the Semitic concept of God as the sole ruler of the world and history. In a monarchy, the king and the dauphin are distinct. Nevertheless, they represent the same monarchy.
So the substance of God is the one monarchy; no confusion or frictions are in it because the Father and Son never disagree, although they are not the same person. So Tertullian comes to his famous thesis that God is one substance in three persons (Against Praxeas 2; 12). The terms 'substance' and 'person' must not be overloaded here by later definitions in philosophical discourse. Tertullian explains substance (substantia) as essence (essentia), a neutral concept, which does not as such refer to a concrete person (Against Praxeas 22). They are unum, not unus (Against Praxeas 25). They refer just to which they refer: there is only one divine substance, his absolute rule over all, his status and potestas (Adversus Praxeas 2), and this expresses itself by three persons. Precisely on behalf of the unity of the kingship of God, the interactions of the persons are accentuated by Tertullian. The most conspicuous are his convictions on the Holy Spirit. When Tertullian wrote his discourse against the modalist Praxeas, Tertullian was an adherent of Montanism (Against Praxeas was written after 217 AD, Bardenhewer 1913:414). At first sight, Montanism seems to be close to modalism: after the coming of the Son, now the Holy Spirit (or as Tertullian, like other Montanists, prefers to say, with reference to Jn 16, 'the Paraclete') has come to the world. It looks like a sequence of God in time, acting in different roles (persona initially meant a role in a drama). However, Tertullian, in spite of his Montanist sympathies, goes the other way. He stresses the specific identity of the Spirit as different from the Son, as he stressed the paradoxical identity of the Son as different from the Father, when he wrote about the nurse who cared for the baby who was the Son (Tertullian, On the flesh of Christ 4; translation Holmes 1885a). Opposing those who opt for a strict monotheism, Tertullian prefers to highlight the different divine persons in God's oikonomia. God is and remains the absolute ruler, creator of heaven and earth. He does not cease to be so. God is also the One who became a human being, as human as a baby which is cared by a human mother and nurse. He does not cease to be human when the Paraclet is sent after his ascension as God's renewing presence in the world. And these three are one and the same God. From the perspective of human beings, there is only one adoration, one obedience, one salvation. In the Semitic context of Carthage, Tertullian does not interpret the Shema of Deuteronomy 6 in the paradigm of mathematics or philosophy. God is one. This means he is the only one to be adored and obeyed, with all your heart, all your soul and all your might (Dt 6:5). He is one because he is faithful: God's work is not fragmentated or even with conflicting aspects. He is so precisely in his coming as the Son and his presence as the Paraclet, by which he is faithful to his creation, and all creatures must praise and serve him as this one God. The anti-Marcionite drive of Tertullian is also the trigger of his antimodalism. The unity of God is not about mathematics but about trust and worship. Noordmans' idea of trinitarian diversification might be useful here. When the Torah teaches and the church confesses that God is one, this is not a numerical concept, but it refers to the fullness of all God's acting in all its diversity (Noordmans 1979:450-452).
Trinitarian theology of the beginning of the 3rd century opposes concepts that keep to God's simplicity at the expense of the paradox of salvation, either by keeping God simple in opposition to creation or by identifying God with salvation history in the pace of time. Therefore, trinitarian theologians stress the paradox of incarnation and the renewing presence of the Spirit.
This kind of theology continues up to the middle of the 4th century. Hilary of Poitiers, just like Tertullian, accentuates the paradoxical features of the life of Jesus -divine and suffering in one person (see, e.g. Hilary of Poitiers, On the Trinity 2.24-27). Athanasius devotes whole his life to the thesis that the incarnate Son is the very same being as the Father, ending with his argument that for our salvation, the Holy Spirit is of the very same being.
If theologians want to plead for a social Trinity, they can better follow these early church fathers than the Cappadocians. For Tertullian, the persons have their own identity. Christians are baptised in the Father and the Son and the Holy Spirit, not in one (Against Praxeas 26). The conversation of the Son with the Father is a true conversation. They are really distinct (Against Praxeas 21-26). But they have the same goal, the same substantial unity of glory by salvation of the world that God created. They are worshipped with the same glory, without any competition. If one searches for a blueprint of ideal human social relations, it is better to follow Tertullian than Gregory of Nyssa.
However, it should be taken into account that the one divine substance is absolute rule, monarchy, according to Tertullian. Classic theology is not easily apt to support modern projections of ideal human relations. Rather, it is confronting to modern (and not only modern) human beings, because the Lord is God and not a human being. And the most surprising is that he is so at the very moment that human beings call for a God who arises in order to put things right in this world, by confronting evil people who exploit creation with his justice, as the prophet Hosea proclaims. The people in the middle of the 8th century BC, the time wherein Hosea lived, called for the day of the Lord (Am 5). Amos says that divine interventions in an unjust world will be worse than all problems people struggle with. Hosea also announces God's judgements over Israel but suddenly prophesies that God will not destroy the disobedient people, 'for I am God and no human being' (Hs 11:9).

The Trinity and anthropology
The Trinity is about God. It is an expression of the fact that God is different from us. Therefore, the Trinity cannot be used for anthropology. The idea of a social Trinity from the beginning related to the very ambiguous concept of the imago Dei (see e.g. Nengean 2013; Van de Beek 2014:184-234). A radical interpretation of the Trinity as a blueprint of anthropology was presented by Snail (2005). Some years later, Wisse (2011, esp. 3-10) extensively opposed participation theology, as he calls it. He contrasts Augustine's theology of the Trinity with that of the Cappadocians and concludes that Augustine does not propagate such participation of the human in the divine, while the Cappadocians, and following them, modern adherents of a theology of a social Trinity, do so. Human relations mirror the relational character of God. Wisse also uses the word 'mirror' (Wisse 2011:6), but participation goes further. Human beings not only reflect the divine being, but also participate in it. The apex of this participation is theopoiesis, becoming divine (Zizioulas 1997:49).
Wisse is right in this claim. Theopoiesis is an important aspect of Eastern theology. However, two questions arise with his claim. The first is if Augustine's mystic interpretation of Trinity does not have a similar unification of human and God. And does his interpretation of the Trinity as Love, with Lover, Beloved and Love itself, not also have a mirror function for ideal human relations, as Moltmann argued? So Augustine and the Cappadocians may be closer than is often argued. However, there is another question: is participation as theopoiesis the same as the mirror character of the modern social Trinity theology? Theopoieis is participation in divine life. It is divine life that gives itself to humanity and even to the whole creation. The Trinity is the base of this divine acting, and this life penetrates everything that is, in a hierarchical process, bringing everything to one glorious unity at the end in the consummation of the world.
However, this process is not the same as the mirror character of the modern social Trinity theology, in which human relations reflect divine interaction. The first is a gradual process of life overflowing and shared, and the latter is a mutual relation of persons. It is about two different frameworks of thought. The former has a hierarchical structure, as an expression of apophatic theology. God is incomprehensible and ineffably high, and human beings share something of this glory. God is not like us, even when we share his life, as all life is given by the Holy Spirit who is Lord and makes one alive. In the Augustinian mystic love of the believer, wherein he or she is loved by God in the way of trinitarian experience, the human participation is much stronger than in the Eastern model: the believer finds his or her identity in God, as for Augustine, 'the search for the self and the search for God are ultimately the same' (Marmion & Van Nieuwenhove 2011:7). And in Augustine's idea of love as expression of the Trinity, the mirror function is much stronger than in speculations about processions and perichoresis.
So it is because of a difference between participation and mirroring. Participation is present in theology both in East and West from the end of the 4th century but in very different modes. The mirror character of the Trinity is more a Western phenomenon, related to cataphatic theology and analogy. Because human beings know who God is, they can reflect him in their own being. If God is trinitarian, he is relational, and consequently, human beings must also be relational. The opposite position, God as One single unity, is rejected by theologians of the social Trinity, for this will be reflected in individualism.
In the discussion about the social Trinity, John 14-17 has an important role. As the Son is in the Father and the Father in the Son, so human beings may be in the Son and in each other. The divine life of love is reflected in the love of believers, both in relation to God and in their mutual relations. However, it is because of difference between an ontological unity and ethical unity. Early Christianity, with its Jewish roots, kept strictly to the ontological distinction of God and human, as is shown in their furious rejection of Gnosticism, wherein all borders were blurred. But they called on human ethical life, which reflects God's acting. The core of this acting is the love of the Son for the Father, expressed in his absolute obedience. So the disciples will be his friends if they do what he commands them (Jn 15:14). Obedience is not an ontological but an ethical category. The chapters in John about divine and human love are in this regard not different from the apostolic paraenesis in the letters of the New Testament.
Similar observations must be made to 2 Peter 1:4, where participation in the divine nature is spoken about. This text is overstretched if it is interpreted as theopoièsis as the presence of divine being (Marmion & Van Nieuwenhove 2011:22). It is rather about a new life. Christians are saved by God's glory and virtue. The Greek has arétè, which the ESV2016 translates as 'excellence'. By this translation, the very point of the argument is obscured: that a Christian will live in virtue (Pt 2 1:5), as a consequence of God's salvation by his virtue. Virtue is the common factor in divine and Christian life. They have escaped from the corruption that is in the world because of sinful desire. Because human beings receive a life of virtue, they participate in what is divine, but this does not mean they become gods or even divine, which would be a blasphemous idea.
For the Cappadocians, too, theopoièsis means participation in divine, eternal life. In their hierarchical theology, it is far from them even to suggest that humans become God. Theopoièsis is not about divine ontology but about human ontology, by participating in the divine life. There is participation but at the level whereon created beings can share what divine essence provides. Their theology is far away from the modern Western discourse on the social Trinity with relations of human beings who would reflect three divine persons. The whole modern idea of the social Trinity is far beyond their horizon, as the patristic scholar Eginhard Meijering once remarked. 'It is important not to read into the Cappadocians later personalist anthropological concerns … They were not aware of the dangers of individualism' (Marmion & Van Nieuwenhove 2011:76; see also Coakley 1999).

Back to the basics
When working on the Trinity, it is striking how different theologians explain it, and it is just as amazing how different exposés about the Trinity by earlier theologians are interpreted. Is Moltmann correct in his interpretation of Augustine? Or is LaCugna right? Or should we follow Wisse? Is the Trinity to be mirrored in human relations? Or is this the worst we can do? Do the processions have priority or the persons? What is the meaning of perichoresis? As many heads, so many opinions. Theologians seem to each develop their own design of the Trinity, as Marmion and Van Nieuwenhove (2011) rightly say.
Theologians claim that their anthropology reflects divine being and life. The diversity of positions shows that it is rather the other way around: ideas about ideal humanity are projected on God. The Trinity is an ideal concept for such projections, precisely because it has been a neglected topic for centuries. Suddenly theologians discover there is, in a forgotten corner of the theologian cupboard, something as the Trinity. This can be made useful for new ideas -Barth uses it for revelation: God reveals himself as 'der Offenbarer, die Offenbarung und das Offenbarsein' (Barth 1981:311). It is remarkable that Barth shifts Augustine's idea about the Trinity as three aspects of love to three aspects of revelation. Epistemology takes the core of theology over from relationship. Other theologians use the Trinity for God's acting in the world (Rahner), for salvation history (Jenkins), for God's relation to humans (Berkhof), for mutual relations of human beings (Moltmann), for opposing individualism (LaCugna), for promoting Greek theology (Zizioulas). They dig up old sources on the Trinity which were not in the centre of theological research for a long time and interpret them according to their interests and introduce them into a context that is totally different, without due hermeneutics. Trinitarian theology has become booming. It is time to go back to the basics. It will be better to leave all those speculations behind and to turn to what is really at stake in the doctrine of the Trinity.
Exposés on the Trinity normally use general concepts when referring to God, such as person, love and relation, and by these, they develop their trinitarian theory. The earliest discourses on the Trinity are not about concepts but about persons, not person as a concept but as a real living person. And they deal with acting, not with theory. For theologians such as Tertullian, Athanasius and Hilary of Poitiers, the Trinity is that God is present as the Father, the Son and the Holy Spirit, and they are present as the omnipotent Creator, the suffering Lord incarnate and the Spirit who sanctifies the church. That is the one God. When Tertullian uses the word 'substance', this is not polished by philosophical reflections but only tells that the divine monarchy is the substantial being of God who acts in the three. No more and no less. It is just telling what it is. God is as he is and he acts as he acts. One in three. Human beings cannot understand this; they can only adore him.
Hilary is very clear about this. Trinity is just a word which refers to this reality, which cannot be explained by comparison with other phenomena (Hilary of Poitiers, On the Trinity 1.7-8). God is incomparable. This does not mean that he cannot be known. Hilary keeps to the 'conviction that His is a greatness too vast for our comprehension but not for our faith' (On the Trinity 1.8).
He is precisely known as trinitarian, as the Father, the Son and the Spirit. This is sufficient. Christians should not speculate about this but celebrate it in the eucharist and live it in a Christian life: [F]aith ought in silence to fulfil the commandments, worshipping the Father reverencing with Him the Son, abounding in the Holy Ghost, but we must strain the poor resources of our language to express thoughts too great for words. (On the Trinity 2.2) Worship and life -that is the best theology of the Trinity. It must only be a matter of discussion when heretics propagate other ideas (On the Trinity 2.2; see also 2.5). This is the theology on the Trinity of the church before the church became socially acceptable and had to become on the standards of dominant philosophy. Hilary and Athanasius are the last representatives of this theological mood. They did not fit into the new reality of the Christian empire, and consequently, they were exiled by the Christian emperor. Athanasius was exiled to Trier in Germany several times, while Hilary was sent to the present Turkey. In both cases, the exposure to a new context and new ideas strengthened their convictions. They do not have theology which supports common interests. It is a theology of God acting, most of all acting where nothing divine is left, and God is present as an executed criminal who is a danger for political stability. He is God who comes as the saviour of all human beings, even if they live outside the borders of the empire, be it Christian or not. For Tertullian, this was a motive for refusing to go into the army (The chaplet 12, translation Thelwall 1885): [T]he heart of the matter is that the doctrine of the Trinity is not an abstract mathematical puzzle, not the articulation of the rhythm of life, nor the projection upon the ultimate of the manifold triplicities that a little inspired imagination can easily suggest to us. It arises from the fundamental recognition that Jesus Christ is Immanuel, God with us, a recognition which is itself enabled by awareness of participation in the Spirit in that same mystery. (Heron 1983:172-173)

Conclusion
Theological discourses on the Trinity are very diverse. Each theologian has her or his own proposal. Reading and reading again such proposals is tiring and at the end even boring. Hearing, and even more doing, what Hilary advises gives breath and joy: celebrating and living that God has become a human being on behalf of us and our salvation makes us alive, because the omnipotent Creator is present in human beings. Meijering (1996:111) says that Athanasius is the great champion of theology of the Trinity. When reading discourses on the Trinity, one would not expect this. In overviews on the doctrine of the Trinity, usually no chapter is devoted to him. One must be a patristic scholar for such statements; modern systematic theologians would not suggest it. Maybe systematic theologians can learn from patristics -if they are willing to not use the fathers for their own ends.