When most Christians try to describe God, they tend first to think of God by discussing his existence and his character, and only come to the Trinity as an afterthought. However, as DB Knox, former principal of Moore Theological College, wrote: “The doctrine of the Trinity is the foundation of the Christian religion”.
The Athanasian Creed, the classical statement of the doctrine of the Trinity, holds belief in the Trinity as absolutely essential for the Christian:
Whosoever will be saved, before all things it is necessary that he holds the catholic faith. Which faith except everyone do keep whole and undefiled, without doubt he shall perish everlastingly. And the catholic faith is this: that we worship one God in Trinity and Trinity in unity, neither confounding the Persons nor dividing the Substance …
The Church Fathers took such a strong stand because the strict monotheism of their heretical opponents relegated Jesus to the status of a sort of demi-god. But more than this is true: the doctrine of the Trinity underpins our very existence as Christians; it gives a unique shape to the Christian life.
What could tempt us to neglect the doctrine of the Trinity? First, we may be so concerned to preserve what is true from the attacks of less orthodox theologians that we forget to apply that truth to the real world. We may forget to ask: what does the doctrine of the Trinity mean for us? Can we actually live the Trinity? Many Christians see the Trinity as an arid metaphysical speculation designed to keep theologians busy on the other six days of the week. It is not generally given practical significance at all; it is applied neither to our worship nor to our witness. Writers and preachers have not often presented the doctrine of the Trinity in such a way that it becomes a reality in the concrete spiritual life of Christians. Will someone ever publish a book entitled What’s So Amazing About the Trinity?
Second, Protestant evangelicalism, as a Christian movement shaped in the controversies of the Reformation and the revivals of the 18th century, is distinguished from other forms of Christianity by its teaching about salvation. That is, what makes evangelicalism different (along with the authority of the Bible) is its insistence on the centrality of the cross and justification by faith alone. It actually holds in common with Roman Catholicism and Eastern Orthodoxy the doctrines of the Incarnation and the Trinity. The Trinity is assumed by evangelicals; we are far hotter under the collar about the salvation doctrines. We have given much less attention to the doctrine of God.
I wish to argue that the Trinity is a very ‘practical’ doctrine. It changes the way we worship, pray and relate to others. Certainly this has been my experience. I will not here attempt a detailed definition or proof of the Trinity; instead, I shall ask what use is the Trinity, or what difference can it make to our faith? For the Trinity is a gospel doctrine through and through. There is always, of course, a reciprocal relationship between what we think and what we do: what does thinking about the Trinity lead us to do?
The doctrine of the Trinity names our God
What use is the Trinity? The Trinity identifies our God: it helps us to name him and to know him, to speak to him and about him. In a world that presents us with a smorgasbord of gods, the Trinity specifies who it is we worship—”he who raised Jesus from the dead” by the power of the Spirit (Rom 8:11). In the West, ‘God’ has been turned into an abstract philosophical concept or a tricky metaphysical problem. In the East, either the god named Allah or the multitude of deities and spirits that are the object of the various Eastern religions are worshipped. When we say ‘God’, it is no longer to be assumed that there is a common understanding of the term. Certainly, the God of popular understanding—the God of cartoons and jokes and civic prayers—is not the God we Christians worship. Which God is he?
The Hebrews knew their God by the literally unspeakable name, ‘YHWH’. God was also identified by what he had done: “I am YHWH, your God, who brought you out of the land of Egypt” (Exod 20:2). Baal was not God, YHWH was God, as Elijah so clearly demonstrated (1 Kgs 18). He was further identified as “the God of Abraham, Isaac and Jacob”, immediately recalling his relationship to Israel’s forefathers. The New Testament gospel is a renaming of this same God in the light of the resurrection of Jesus. The New Testament writers found themselves referring to God as “him that raised from the dead Jesus our Lord” (Rom 4:24; see also 1 Cor 15:15, 2 Cor 1:9, 4:14; Gal 1:1; Col 2:12; 1 Pet 1:21).
Furthermore, the famous words of Jesus himself in Matthew 28:19 urge baptism “in the name of the Father, and of the Son and of the Holy Spirit”. This formula is rather odd: it attributes three owners to a single common name. And yet it is this name that is to mark the baptism of Christians—the symbol of their cleansing from sin and raising to new life. It is this name that Christians now bear. This trinitarian name reminds the Christian of what the Father has done for me by the Son and does in me by the Holy Spirit.
The doctrine of the Trinity explains prayer
The doctrine of the Trinity helps us in our prayers. As we have seen, we can identify the object of our worship in the Trinity. Through biblical, trinitarian lenses we can see how our prayers may be heard and understood. Prayer is part of our sharing through the Holy Spirit in the relationship of Jesus, the incarnate Son, with his Father. As is made plain in Hebrews, there is only one mediator between God and humankind. We participate in his intercessions to the Father by virtue of his atoning work for us as our sole High Priest, sprinkling our consciences clean. Put plainly, in prayer we share in the family of God.
Paul uses the metaphor of adoption to explain how in Christ we are brought into the very family of God. Romans 8:9-17 explains how the Spirit Christians receive is one of ‘sonship’, one that enables us to cry out “Abba, Father!”. It is not because we are created human beings that we can address God as Father; it is because we share in the Son-ship of Jesus by being his “co-heirs”—by having within us the Spirit of Christ himself. Only then can we can we truly call God “Father”.
In Galatians 4:1-7, Paul expresses in full the liberating impact of the coming of the Son. We are freed from the “elements of the world” that once enslaved us. Paul famously here includes both the Law (torah) and demonic powers under the heading of “elements of the world” (called stoicheia in Greek). Being able to call God “Abba”, itself the work of the Son’s Spirit in us, frees us from the slaveries of the law and the spirits. What makes true Christian prayer so radically different from prayer in other religions is that it is founded on the trinitarian shape of grace—the access to God the Father that is freely ours by the Spirit in the name of the Son. We can experience a palpable freedom and acceptance on the basis of this magnificent gospel.
I have only ever been apart from my family for Christmas once—about a decade ago. However, a friend’s family invited me to their table. When I arrived, I was greeted with warmth, given presents and included in the rituals and the banter of the family. My fears of loneliness were soon dispelled. It was an overwhelming and happy day! Could this be an inkling of what Christians enjoy— trinitarianly—in their prayers?
The doctrine of the Trinity shows us how to love
As DB Knox wrote in The Everlasting God, the triune nature of God shows us that relationships are central to being a person. The doctrine of the Trinity teaches us that we are united to one another in the fellowship of the Holy Spirit. The Spirit not only works in us to acknowledge Jesus as Lord and so approach the Father, but also binds us to one another in love. In 1 Corinthians 12 Paul wonderfully illustrates the unity in diversity of the congregation by means of trinitarian language. Just as with the Trinity there is both a difference of role and yet a oneness, so with the fellowship of believers. It is the “same Spirit” that these diverse members have in common, uniting them as the body of Christ to one another. The members of the church cannot sever themselves from one another without damaging themselves. They are interdependent. Love—the never-failing, humble, forgiving love of 1 Corinthians 13—is the key.
The church then, is not merely a sharing of a common passion, common thinking, or even a sense of high regard for one another. It is no mere club. Those who are in Christ are tied far more profoundly and securely to one another than that. All sorts of difficult diversities are accommodated in the body of Christ. Love is the means by which our spiritual unity can be demonstrated. In our acts of love for one another, we express outwardly our connection to one another and, in Christ, to God.
We must be cautious, however, when speaking of the way in which the loving community of Christians reflects God as Trinity. One late 20th-century theological fad is to apply the Trinitarian idea of perichoresis to the church. That piece of theological jargon means ‘mutual indwelling’. It is the way in which theologians have explained how the three persons of the Trinity are related to one another: they live ‘in’ each other, they are bonded to one another in a unique way. They love each other totally. The language of John 14—the Father and the Son being ‘in’ one another—is what this term helps to explain. If the three divine persons enjoy ‘perichoretic’ relationships with one another, so too, it is said, does the church, which worships Father, Son and Holy Spirit. God is love; shouldn’t we be like him?
This is dangerously simplistic thinking. Human beings are like God, but we are not, and will never become, God! The bond between the Father, Son and Holy Spirit is substantially different to the way human beings relate to one another in church. For one thing, human beings can only reflect God as creatures with bodies. We are not God, but only resemble him. This will be true even in eternity. For another, the inescapable shadow of sin means that within the present age, human beings cannot be made into the perfect images of God, despite the promise of our transformation in the world to come. The relationships of pure love within the Trinity are indeed the model to which the sin-marred, human church ought to aspire. However, within history, at any rate, the realization of this ideal will be limited.
Furthermore, within the present world of sin, the love that has as its goal the perfect world to come ought to follow the form of the cross of Christ. In the present evil age, the Trinity loves the world by giving up the Father’s one and only Son to death (John 3:16). The love that is needed for a sin-stained world is a self-giving love. It is a love that bleeds. The Trinity does provide a model for our relationships in community this side of Christ’s return, but this model is best seen in the passion of God for the salvation of the world such that he would sacrifice his Son. The doctrine of the Trinity drives us to love in practice.
The doctrine of the Trinity leads us to the cross
The focus of the Christian life must be the cross of Jesus Christ. However, the cross itself only makes sense when viewed with trinitarian eyes. On the cross, we do not see an innocent Son arbitrarily punished by an impassive Father for the sins of others. Evangelists and song writers have often unintentionally caricatured the cross as some kind of horrible divine child abuse of a blameless Jesus by the stern, implacable Father. Instead, we see “the Judge judged”, to quote the pithy phrase of theologian Karl Barth. He is not an innocent bystander to the process of reconciliation, or its victim; he is intimately involved with it, laying down his life willingly—only to take it up again (John 10:17). He goes to the cross freely and obediently.
In the cross, more than on any other stage, God revealed himself as he truly is. In one sense, his glory and majesty were completely concealed in the ugliness of Calvary. And yet, ironically, nowhere else does he demonstrate his character more clearly. The lowliness and humility of the cross show us that God is not far off and uninvolved with us, but that he is committed to us and near to us in suffering. The God we serve is the God who serves. Even within the Trinity, there is obedience and humility—that of the Son towards his Father.
Does the Father desert the Son upon the cross? We sing “deserted by God, man and friend”, but is this really what happened? How should we interpret the cry of dereliction: “My God, my God, why have you forsaken me?” (Mark 15:34)? In one sense, the man on the cross is truly godforsaken, bearing at that moment the sins of the world. However, the emphasis of 2 Corinthians 5:19—”God was in Christ reconciling the world to himself”—and other passages, such as Philippians 2:5-11, Hebrews 5:7 and Romans 8:32, indicate that reconciliation was an event that occurred within God himself. Even at the moment of deepest darkness, God the Father and God the Son were acting together to bring about a reconciliation with the world. Our salvation is achieved entirely by God.
The cross is also a reminder to Christians that they should not be surprised if they suffer. Once again, the doctrine of the Trinity gives us practical help. Suffering plays a large part in the idea of our union with Christ, as Romans 8 and 1 Peter 4 illustrate. It is by sharing in Christ’s sufferings that we may hope to share in his glory also. Furthermore, in our feebleness, this Spirit of Christ helps us, interceding for us and drawing us to the Father (Rom 8:26ff), speaking our groans for us. In this way, the trinitarian shape of our spiritual lives offers a unique comfort in time of trial. We do not suffer alone, nor do we suffer in vain. There is purpose in our suffering.
Putting it into practice
The Trinity is, then, a very important Christian doctrine to put into practice. Without it, our faith is far less distinct from any other religion. With it, we see the deepest realities of what it means to be a Christian. It is a truth that needs to be revisited regularly in sermons, Bible studies, youth groups and the like, rather than left high and dry in theological libraries.
The doctrine of the Trinity describes the name of our God—a God unlike any of the other ‘pretenders’ to the title. It also gives direction to our prayers, reminding us that we only come before the Father through sharing in the sonship of the Son and receiving his Spirit. It teaches us to approach God in humility, as adopted children who are ‘at table’ with him purely by his grace.
The doctrine of the Trinity also teaches us the true meaning of love, because it shows us the sacrificial nature of God at work. This rich and marvellous truth is so utterly foreign to worldly thinking about love that it merits deep reflection: “Behold, what manner of love the Father has given unto us” (1 John 3:1). Finally, the Trinity reveals God to us in the agony and glory of the cross of Christ, where the relationships within the Trinity are stretched to an almost incomprehensible breaking point. When we reflect on what the suffering of the Son achieved, it puts our own suffering in perspective and enables us to see that to suffer for him is to suffer with him. And when we are in the midst of suffering, that knowledge is immensely practical.
