How can God be both three and one? The logic of the Trinity

‘Hear, O Israel: The Lord our God, the Lord is one.’ (Deuteronomy 6:4). This is the uncompromising confession at the heart of Jewish, Christian and Muslim faith. There is only one God worthy of worship, as there is only one who is the ‘greatest conceivable being’ (Anselm, Proslogion). Thus, we are to ‘Love the Lord your God with all your heart and with all your soul and with all your strength.’ (Deuteronomy 6:5). This is because God is ‘the Good’, and as it is right to love what is good, we should seek to adore the source of all goodness (Plato, Republic, Bk. VII). Thus, as opposed to polytheistic religions which claim there are lots of gods, pantheism which claims the world is god, and atheists who say there is no God, monotheists profess there is but one God of everything.

‘Therefore go and make disciples of all nations, baptising in the name of the Father and of the Son and of the Holy Spirit.’ (Matthew 28:19). This is the ‘great commission’ of Christianity, a command from Jesus after His resurrection to His followers to bring all peoples into the Kingdom of God. Baptism is the ritual of being submerged in water and rising out of it, a response to the grace of God in committing to turn away from one’s previous way of life and following the way of God (Matthew 4:6). Thus, one would only be baptised in name of God, as God is the one who enables such a change to take place in a person’s life (Romans 7:4-6). Yet this entails a quandary, for although God is one, the Christian is baptised under three names: the Father, the Son and the Holy Spirit. The question is, how can God be both three and one?

Last week, I sought to try and articulate the Gospel in a form which is both relevant to a secular context and faithful to the salvation God has wrought in Jesus. I did this by focussing on Paul’s lecture to the Athenians (Acts 17:16-34), which involved dissecting and briefly exploring the different segments of what he proclaimed. At the beginning of his presentation, he argued that there is but one God, which we saw meant there is only one meaning of life, which is to worship the true God. Yet undoubtedly, one will eventually have to say who this true God is – if we are to love Him, we ought to have some idea who the Lord is. The Christian recognises that God has revealed Himself as totally one, yet also as Father, Son and Spirit, and so concludes that God is Triune. Thus, as the heart of the Gospel message is the Trinity, the one God, who has called us away from sin in light of his oncoming judgement. As such, we as a Church ought to give an account of who God is as the Trinity if the question should arise (1 Peter 3:15).

However, this is no easy task. Generations of people have wrestled with the notion that God is three and one, coming to all sorts of conclusions and positions. By its very nature, the concept of being triune seems strange to us, and anyone who seeks to understand more often finds by the end of their quest they know a lot less! Hence, this article will try and offer some reflections on how one might approach the doctrine of the Trinity, why we should believe it is the best account of how God has revealed God’s self and how it is best to be a witness to God as Triune.

1)      What is the doctrine of the Trinity?

The doctrine of the Trinity was officially stated at the council of Nicaea in 325 A.D., and later refined at the Council of Constantinople in 381 A.D. Amongst other issues, the attendees of these meetings sought to identify what it is precisely the Christian community believes about who God is, in light of the ‘Arian Controversy’. Arius believed that God’s nature precludes any change. From this he noted that if God were to become human, as He would have to if Jesus were God, then God would have to change, by taking on the property of being a man. As such, Arius argued Jesus could not be God, because if God’s nature does not allow for change, then He cannot become a man (Letter to Eusebius of Nicodemia). Moreover, the Holy Spirit also could not be God, because the Spirit works within the world, and as everything in the world is subject to change, that must mean the Spirit is subject to change. However, as God cannot change, God cannot be in the world. Thus, Arius concluded neither the Word (Jesus) nor the Spirit is divine, with only the Father being Holy.

This position caused a great deal of controversy within the Church, causing a great theological split. Hence, the council of Nicaea was convened to decide whether Arius was right to claim on the Father was divine. The result did not go Arius’s way, with the council concluding the Father, Son and Spirit are all God (for reasons we shall examine later). But how exactly did they define the relationship between the oneness of God and the Threeness within God?

The Nicene-Constantinople Creed states the following: the Father, Son and Holy Spirit are ‘consubstantial’, yet three distinct ‘hypostases’. Consubstantial means to be of one substance. Hypostases is defined as an ontologically real and distinct person. So the council argued that God is one nature with three persons, or three persons with one nature (whichever way round works for you). You will notice this is primarily a negative definition: it states what cannot be left out of an account of who God is. This is in line with apophatic tradition, which claims at best we can say only what God is not, for as God is beyond human comprehension, we can only say God is not like the things we observe. So for example, if a person says there is more than one God, then they violate the fact that God is a being with one nature, and it cannot be shared across beings. Moreover, if one claims that God is really just one person who plays different roles, that person has made a mistake because any adequate account of God must keep distinct the reality of the three persons. This makes sense, as the council is responding to the Arian Controversy, and was seeking to define the boundaries of what it is appropriate to say about God. However, it does mean that it is not specified how God is three and one (as later theologians tried to do). Rather, it just secures the doctrine of God as being one in terms of nature, and three in terms of persons/centres of agency.

2)      Why should we think that God is Triune?

The doctrine of the Trinity is a response to the revelation of God and trying to understand what God has revealed about God’s self. As we saw at the beginning of this article, Yahweh is revealed as being unique and one (Deuteronomy 6:4), yet as also being three persons (Matthew 28:19). In the life of Jesus of Nazareth we see this most clearly. As an orthodox Jew, Jesus upheld the truth that there is only one God (Matthew 22:36-40).  However, at the same time we observe that there are three, simultaneously coexistening agents who are integral to the acquisition of human salvation: the Father, Son and Holy Spirit (Luke 3:21-22). Indeed, if we take the baptism of Jesus as a microcosm of the whole soteriological process, we can see the inner differentiation within the one God. In His baptism, Jesus identified with sinners and stood with them, taking upon himself their sin and bondage to evil as a precursor for His crucifixion, which would atone for their transgressions and free them from the power of darkness (Romans 6:1-4). And in rising out of the water, we see a foreshadowing of the resurrection, where new life, transformed life, free from death and suffering is drawn out. In this act of ultimate salvation, we see the Father’s vindication, blessing and exaltation (Luke 3:22), the Son’s obedience and sacrifice to the Father on behalf of humanity (v.21) and the Spirit descending upon Him in order to further His ministry and conquest of evil on behalf of the Father (v.22). Thus, we can see in this event the whole story of the Gospel, which revolves around the interplay of the Father, Son and Spirit. This requires their coexistence as the one God.

Indeed, this example of the Father, Son and Spirit’s simultaneous existence delivers an insight into why the Church understood them to be the one, divine God. Of first importance, we should remember that God is uniquely one – there is no other who is worthy of worship. Yet God is also categorically distinct from the world, as God is fundamentally different to the objects and beings we are familiar with. For example, when we say God is one, we do not mean God is like one finger, or one table. We primarily mean there is nothing else like Yahweh, no one else is Holy like Him. Moreover, God is the only one can save humanity and restore us to a right standing before Him (Psalm 62:1). For the Scripture states all have sinned, that no one is perfect and all have done wrong against God (Romans 3:23), which entails that only God can forgive that which is done against Him (Mark 2:7). Hence, only the one, true God can save humanity from its enslavement to sin and the punishment it deserves.

At the same time, we observe that the Father, Son and Spirit are all revealed as being integral to single operation of salvation, performing different functions in the process. All the actions of God find their origin in the Father, they proceed through the Son and are perfected by the Holy Spirit (Gregory of Nyssa, A letter to Abalius). For example, the Father ordains from before the creation who will be saved (1 Peter 1:2), the Son is the one who brings this to fruition through His life, death and resurrection (John 6:35) and the Spirit brings us into participation with the Trinity (Ephesians 3:19). Thus, the Father, Son and Spirit perform the one operation, salvation, whilst taking upon themselves different functions in accordance with their personage.

This leads to the startling conclusion that the three persons of Father, Son and Spirit are the one God. For if we ask what makes it possible that one can save humanity, the answer is that one only has sufficient powers to be the source of salvation if one has a divine nature (is God). Thus, the Father can only save if and only if He is God. Likewise, the Son can only save if and only if He is God. And the Holy Spirit can only save if and only if He is God. Thus, the Father, Son and Spirit must all be God. Yet as there is only one God, the Father, Son and Spirit must not be multiple deities, but the unique, categorically distinct one divine nature. As such, the Church has discerned that because one can only save if one is God, that there is one God and that the Father, Son and Spirit save, it follows the one God is triune. Thus, in virtue of the saving activity of God, we can know who God is. We can summarise this argument in a logically valid form (that is, if the premises are all true the conclusion cannot be false):

1)      There is only one God.

2)      God alone can save.

3)      The Father saves.

4)      The Son saves.

5)      The Holy Spirit saves.

6)      Therefore, the Father, Son and Holy Spirit are the one God.

This argument reveals why we should think of God as Triune. For if God saves as according to the Bible, then we can only make sense of what the Father, Son and Spirit do if we understand them as divine. This should be the pillar of our evangelism when witnessing to who God is, that the ‘economic’ activity of God reflects His ‘immanent’ nature (Barth, Church Dogmatics Vol.1). For whilst we may offer pithy analogies and more positive accounts of how the three can be one, ultimately this goes beyond the doctrine, and can often lead to theological difficulty. Rather, if we ask what is required for one to save, and then show how the one God is revealed as saving in the simultaneously existing Father, Jesus and the Spirit, we can see the inner logic of faith that God must be Triune. This is faithful to the Scripture, whilst also recognising the negative nature of the doctrine: Scripture does not provide an in depth study of how God can be three and one, nor does the Nicene Creed and neither should we, as such thought is mere speculation. Instead, we should affirm that any account of God which does not recognise God is one divine nature with three distinct persons, the Father, Son and Holy Spirit, is inadequate as a response to God’s revelation. So affirm the essentials in accordance with Scripture, for the Trinity explains how God saves the way God chose to save.