How does the Trinity work? According to certain modernist epistemologies, this is a crucial and fair question, and any preacher of the gospel should be expected to explain it to any rational inquisitor. The Trinity can fairly be understood in this instance as an object of philosophical inquiry apart from faith – as though the concept might contain some secret that will unlock insights for the world outside the community of faith. However, Scripture never presents the Trinity this way – in fact, it never even uses the term Trinity. That is because the relations inside the Godhead are not meant to be reduced to metaphysical speculation outside of the life of the God who reveals them.
In Scripture we are not introduced to something called Trinity, and left to guess what that means on the evidence. The concept of Trinity is not a pre-existing ontological or metaphysical category into which the Christian conception of God should be expected to fit. We as Christians do not have a Trinity besides that which is revealed in Scripture. For this reason we cannot approach the concept of Trinity without first attending to the God who is revealed in Scripture, and in Israel’s history. There we are introduced to God as Father, Son and Spirit, through the history of God’s interactions with creation. “Trinity” is not a revision of the biblical witness, or a reality apart from the life of the God it describes, and thus cannot be understood apart from the reality of this God. Jürgen Moltmann describes a kind of knowing that contrasts with modernist concerns:
For the Greek philosophers and the Fathers of the church, knowing meant something different: it meant knowing in wonder. By knowing or perceiving one participates in the life of the other. Here knowing does not transform the counterpart into the property of the knower; the knower does not appropriate what he knows. On the contrary, he is transformed through sympathy, becoming a participant in what he perceives. Knowledge confers fellowship.
The point of the Trinity is not to unlock the secrets of its operation, but rather to participate in the Triune life through faith. The Trinity is not so much something to be explained, but something to experience. The Athanasian Creed states: “He therefore that will be saved, must thus think of the Trinity.” This does not mean that the doctrine of the Trinity is a proposition to which one must simply assent in order to avoid eternal condemnation, or an arbitrary formulation to decode. As Gary Deddo puts it, salvation “is not some kind of detached independent life in a sphere parallel to God’s own life.” Rather, the Athanasian Creed has as its foundation the notion that there is no life outside of the relationship between Father, Son, and Spirit; a relationship into which we as God’s creation are invited. The rest of this paper will be a doxological reflection on the nature and history of that invitation.
Jesus Reveals God as Triune
Deddo (reading Karl Barth) says that in the life of Jesus “we are privy to the ongoing interaction of the Father with the Son throughout the whole life of Jesus.” Jesus constantly refers to Yahweh as Father, and to himself as Son. This filial relationship is unique, but not exclusive, as Jesus also teaches his disciples to pray to “our Father” (Matt. 6:9). Humanity is seen as having access to this Father through the Son, who both knows and reveals the Father (Matt. 11:27). The Father and Son both relate to one another and exist in perfect unity, as “whatever the Father does the Son also does” (John 6:19). This Father-Son relationship is uniquely devoid of what we have come to expect as natural byproducts of broken human relationships. The fact that this relationship is so completely characterized by love, obedience and trust might make one believe that there is a hint of disingenuousness in describing these persons as separate; yet throughout the biblical witness it is presented as a genuine, dynamic relationship. Jesus and the Father, through their relationship, are healing the broken image of relationships that circumscribe our human imaginations.
Father and Son are also not a transcendent dyad whose love for each other closes them off from further relationships. The Holy Spirit, as the divine presence which empowers Jesus throughout his ministry, presents God as not locked in a narcissistic or solipsistic gaze within Godself but one whose love ecstatically, relentlessly, overflows outside. As David Bentley Hart says, the Holy Spirit is “not simply the love of the Father and the Son, but also everlastingly the differentiation of that love.” This differentiation
perfects the love of God, immanently and economically; immanently completing it as love, deepening it in his “excessive” difference, the further sharing of love, beyond what would be contained in mere mutuality; and economically, by being the differentiation and perfection of divine love “outward,” whereby, graciously, it opens out to address freely (and so to constitute) the otherness of creation.
In the life of Jesus the mutuality that characterizes Trinitarian relationships takes on specific form and direction, in God’s mission of reconciliation. We see, as Deddo puts it, “God himself as himself revealing himself in terms of himself.” In his Incarnation Christ is both the revelation of God and the reconciliation of God, because, drawing from the Moltmann quote above, knowledge of this God invites one into fellowship. Or, as Barth says, “God does not give us something, but Himself.” The (tri)unity in which Jesus reveals God is the essence of salvation for humanity. We are invited into “participation by the Spirit in the relationship Jesus has with us and with the father.” Thus Jesus prays “that all of them may be one, Father, just as you are in me and I am in you. May they also be in us” (John 17:21). The work in which Jesus reveals God to be engaged cannot be seen as incidental to God’s nature, but flows from the excessive love which the Father, Son, and Spirit eternally have for each other.
The cross itself is not an interruption in Trinitarian relations. It is not the moment where the Father callously surrenders the Son in an apparent diminishment of their love. The cross is the moment where the love that each person of the Trinity has for each other is also the love in which humanity finds itself caught up. This love is so strong that that even the death in which we participate cannot break its bonds. The Resurrection is the culmination of Jesus’ triune revelation, in which the three persons of the Trinity are known not as abstraction or as formula but as an event – God raising Jesus through the power of the Spirit (Romans 8:11). “When the early Church Fathers developed the doctrine of the Trinity, they were not painting by numbers; they were finding concepts to express an experience.” God is revealed as Triune in God’s movement towards humanity, in the work of redemption. Therefore any contemplation of the Trinity must not take place in the abstract, but must deal with the God who is revealed in Christ – or, as Barth puts it, “we must not seek to know about God or man except as we look on Jesus Christ.”
The Triune God of Love
The fact that God is love in Godself means that love is not merely a characteristic but constitutes God’s very identity. This answers the question that Michael Reeves puts forth in the first chapter of Delighting In The Trinity: What Was God Doing Before Creation? If the answer is that God became loving at the time of creation, then love may be nothing more than a phase in the history of this God, who was God before being loving and may continue to be God in some future unloving state.
That God engaged in the act of creation does not imply that there was an intrinsic, pre-existing neediness inside God, which was satisfied by that act. As we see the Father in Son in perfect unity, without the insecurities that plague our human relationships, we can see that the act of creation was an overflow of the love which is the Triune persons in relation. Karl Barth continually stressed that the love that the Trinity share is a uniquely free love: that “God seeks and creates fellowship between Himself and us, and therefore He loves us. But He is this loving God without us as Father, Son and Holy Spirit, in the freedom of the Lord, who has His life from Himself.” When we affirm with 1 John 4:8 that “God is love,” we are not trying to fit this God into a preset definition of love, or even worse, trying to affirm something about God besides that which God has revealed in Christ. Rather, love itself is redefined in the gratuitous Trinitarian display of love by “the One who loves in freedom.” Reflections on the Trinity, and participation in the love of God through the Spirit, help heal our flawed expressions of love, drawing us deeper into the bond which holds Father, Son and Spirit together, along with creation, which through them is being reconciled. Ross Hastings writes, “If the church is an icon of the Trinity, then similarly it will be characterized by a profoundly deep relationality in its inner life, but this relationality will have an orientation toward the world.” This is the goal of Trinitarian study and reflection – not a solved equation, or metaphysical speculation, but actual reconciliation in relation to God and the rest of creation. To know the Trinity is to venture outside the bounds of philosophical or scientific neutrality, and to hear the divine invitation: “you may allow yourself to be loved by me.”
 Jürgen Moltmann, The Trinity and the Kingdom: The Doctrine of God (Minneapolis: Fortress Press, 1981), 9.
 James Sullivan, “The Athanasian Creed” in The Catholic Encyclopedia. Vol. 2, (New York: Robert Appleton Company, 1907).
 Gary W. Deddo, “The Grammar of Barth’s Theology of Personal Relations.” Scottish Journal of Theology 47, no. 2: 187.
 Deddo, “Grammar,” 193.
 Unless otherwise stated, all Scripture is taken from the NIV.
 David Bentley Hart, The Beauty of the Infinite: The Aesthetics of Christian Truth (Grand Rapids: Eerdmans, 2004), 176.
 Ibid., 176.
 Gary W. Deddo, “From Christology to Trinity,” (Class Lecture, Northern Seminary, March 7, 2016).
 Karl Barth, Church Dogmatics II/1, (Edinburgh: T&T Clark, 1957), 276.
 Deddo, “Grammar,” 187-188.
 Paul S. Fiddes, Participating in God: A Pastoral Doctrine of the Trinity (Louisville, KY: Westminster John Knox Press, 2000), 5.
 Karl Barth, Church Dogmatics II/2, (Edinburgh: T&T Clark, 1957), 150.
 Michael Reeves, Delighting in the Trinity: An Introduction to the Christian Faith, (Downers Grove, IL: IVP Academic, 2012), 19-38.
 Karl Barth, Church Dogmatics II/1, 257.
 Karl Barth, Church Dogmatics II/1 322.
 Ross Hastings, Missional God, Missional Church: Hope for Re-Evangelizing the West (Downers Grove, IL: IVP Academic, 2012), 87.
 Eberhard Busch, Karl Barth: His Life from Letters and Autobiographical Texts (Philadelphia: Fortress Press, 1977), 415.