Summary: Scriptural support for the Trinity. The contribution of Tertullian.

Augustine said, ‘if you deny the Trinity you lose your soul, if you try to explain it you lose your mind’. The hope today is to avoid both of these pitfalls. But in order to do this, you will need to put your thinking caps on. And you’ll need to think because we are moving around the Bible and putting material together to give us a sense of what God is like in trinity. If you flunked out of school, today you are officially back in school.

We tend to be interested in only what is immediately useful and we are impatient with truth for truth’s sake. Macleod points out that ‘even if the Christian life could be reduced to an endless round of singing and praying (and, of course, it cannot) we have to sing and pray with understanding (1 Cor 14:15)’. God has gone to enormous trouble to teach us the truth about himself and we should surely take some time to learn it. Whilst truth in the Bible is always factual, above all else it is relational. So Jesus says in John 14:6, ‘I am the way and the truth and the life. No one comes to the Father except through me’. To know Jesus is to know the truth. The truth shows us the way and the truth points us to life.

The great thing about truth is that it brings us in touch with reality. And ultimate reality is about knowing Jesus as Lord and Saviour and living each day with him. So the truth about the Trinity is not there for the sake of being there, it is there so that you might have life and have it to the fullest. Paul, writing to the younger Titus, says to him, ‘You must teach what is in accord with sound doctrine’ (Titus 2:1). We need to know not only how we ought to behave as Christians, but also why we should behave this way. Of all the doctrines we can ever study, the doctrine of the Trinity is the most empowering for life in this world.

People in our world want to be loved. People want relationships. People want communication. A lot of advances on the internet are chat rooms and blogs and forums and Twitter and Facebook. These are portals by which people can be spoken to and speak to one another. Mobile phones, texting and emails reflect a deep desire for identity in a fast moving world. We want a sense of belonging, a sense of unity, in a world full of diversity.

All these deep longings are grounded in the fact that we are made in the image of God. We are all born with a concept of God and we need to understand that no person can rise above their concept of God. So we need to get our understanding of God right. There’s nothing more important than answering these questions, ‘Who is my God’? ‘Who do I believe in? Who will I face when I die’?

We begin to understand God correctly when we understand that he exits in Trinity. The Bible doesn’t aggressively argue the truth of the Trinity. The word is not even found in the Bible. In order to demonstrate that God is Trinity we need to show that there is one God, and that the Father is God, the Son is God, and that the Holy Spirit is God. So let’s for a moment consider the evidence in the New Testament for the divinity of the Father, Son and Spirit. I’m really excited about doing this, and I hope the other two of you share in my joy.

The Bible is clear from beginning to end that there is one God. Deut 4:35, ‘the Lord is God, beside him there is no other’; Deut 6:4, ‘Hear, O Israel: The Lord our God, the Lord is one’; Deut 32:39, ‘There is no god beside me’; Ps 86:10, ‘You alone are God’; Isaiah 43:10, ‘Before me no god was formed, nor will there be one after me’; Isaiah 45:5, ‘I am the Lord, and there is no other; apart from me there is no god’; and 1 Tim 2:5, ‘There is one God’.

God reveals himself as one God. Christianity is absolutely committed to belief in one, exclusive and true God. The doctrine of the Trinity says that there is one God who eternally exists in three persons. Where does the Bible say that Father is God? In John 6:27, Jesus refers to God as ‘the Father’. In 1 Cor 8:6 Paul says, ‘yet for us there is but one God, the Father’. Of all the false teachings that I know, none of them deny that ‘God the Father’ is God.

The next thing to needed to establish the truth of the trinity is to show that Jesus is God. Despite the views of others, we see this truth beginning to unravel in John 1:1, ‘In the beginning was the Word, and the Word was with God, and the Word was God’ (Jn 1:1–2). As we keep reading we learn that this Word is the Lord Jesus. Verse 14, ‘The Word became flesh and made his dwelling amongst us’ (Jn 1:14). Jesus, who is God the Son, was with God the Father and he became a man.

I’ll give you a few more verses. In Jn 8:58, Jesus is speaking and he says, ‘I tell you the truth, before Abraham was born, I am’. His critics wanted to stone him because Jesus maintained, right to the cross, that he was eternally God the Son. That he existed before Abraham, that he is the great ‘I am’ revealed in Ex 3; the Son eternally co-existing with his Heavenly Father. Thomas gets it right in John 20:28 when he declares, ‘My Lord and my God’.

Outside the Gospels we can go to verses such as Rom 9:5, ‘Christ, who is God over all, be forever praised’. Titus 2:13 speaks of ‘our great God and Saviour, Jesus Christ’; and 1 John 5:20 declares that Jesus is ‘the true God and eternal life’. There is one God—the Father is God and the Son is God—and the Holy Spirit is the third person of the Trinity.

The Holy Spirit is not a power or unseen force, rather the Spirit is a ‘He’. The Spirit is a person like the other members of the Trinity. Check out 2 Cor 3:17–18 where Paul says twice that the Lord (which is a title for God)—that God is the Spirit. The Lord is the Spirit. And again in Acts 5, the scene where Ananias and Sapphira steal from God by withholding money.

In verse 3 of Acts 5, Peter rebukes Ananias and says, ‘Ananias, how is it that Satan has so filled your heart that you have lied to the Holy Spirit and have kept for yourself some of the money you received for the land?’ Then in the next verse Peter says, ‘You have not lied to men but to God’. The Holy Spirit is God. It’s bad enough to lie to a man, but you, Ananias have lied to God. The Holy Spirit is God and you have lied to him.

The Bible clearly attests to one God who exists in three persons. A verse often quoted to support the Trinity is 1 John 5:7, ‘For there are three that testify in heaven: the Father, the Word and the Holy Spirit, and these three are one’. These words may be true, but they are not present in many early manuscripts. Its dodgy to use this reading to support the case for the Trinity. There’s other evidence far more reliable, and so the NIV wisely puts this verse in the footnotes.

My favourite text for arguing the Trinity is 1 John 4:8, ‘Whoever does not love does not know God, because God is love’. God has always been love—even before the creation of the world. And love only makes sense if there is someone to love outside yourself.

In his book, Mere Christianity, C.S. Lewis says:

’All sorts of people are fond of repeating the Christian statement that ‘God is love’. But they seem not to notice that the words ‘God is love’ have no real meaning unless God contains at least two Persons. Love is something that one person has for another person. If God was a single person, then before the world was made, he was not love’.

‘God is love’ is another way of saying that ‘God is Trinity’. Some religions teach that God was lonely and he needed to make someone to love. But the Bible says that God lacks nothing. Each person of the Trinity loves the other person. Within the Trinitarian nature of God there is perfect love—perfect friendship, perfect relationship, perfect unity, perfect communication. Within the Trinitarian community of Father, Son and Holy Spirit, there is complete and perfect and binding love. you and I were made to love and be loved. And we have no idea what love is until we go to the source of love—God is love.

Let’s pause for a moment, take three deep breaths and pull some threads together. The New Testament reveals a God who exists in Trinity. The doctrine of the Trinity is not arrived at by human reflection. It is a doctrine that comes from listening to the Word of God and so it relies upon the authority of Scripture. He who speaks to us declares that he is the only God. Others gods are phantoms and mirages. The living and true God reveals that he alone is one.

Our understanding of the Trinity crystallises in the Bible with the coming of Jesus and the participation of the Spirit in our salvation. It is an historical fact that the idea of the Trinity has never occurred to anyone in any of the religions of the world outside the Christian revelation. To the secular mind, the Trinity is incomprehensible and absurd. But the doctrine of the Trinity is the glory of the gospel. Through it we understand not only God’s nature and his relationship to us, but we come to understand our own nature and our relationships with one another.

So we can say these things about God: (1) There is one God; (2) salvation comes from a three-fold source: the Father, the Son and the Holy Spirit; (3) Christ is God; (4) The Holy Spirit is God; (5) we must not confuse the Trinity: the Father is not the Son, nor is the Son the Holy Spirit.

Each of these beliefs in themselves are not difficult to understand. The problem arises when we try and hold these truths together. How can God be one and three at the same time? In what sense is the Son God? What is the relationship between Father, Son and Spirit? Throughout the history of the church these points have been challenged and Christians have been forced to think carefully about their statement of the Trinity. The fact that we are so comfortable with Trinity is because the battles have already been fought and won, and we enjoy the spoils of victory.

Amongst many men, there are four men who have made a substantial contribution to Trinitarian thought: Tertullian, Athanasius, John of Damascus and John Calvin. As Macleod points out, these ‘were men of outstanding personal piety, actively involved in human affairs, deeply concerned for the church and quite willing to suffer for their beliefs. They taught and they defended the doctrine of the Trinity because, at the deepest level, it mattered to them’ (Macleod, Shared Life, 49).

We think of academics in their ivory towers declaring with all wisdom what the masses should believe. But men such as Tertullian were not dry, hard-nosed, self-opinionated academics. These men were Christians and they defended the truth of Bible even when the odds were stacked against them. We would be honoured to have anyone of these men in our church family. God used the faithfulness of these servants to preserve his Word from attacks which, at their core, denied the gospel of salvation.

Today I’d like us to focus on Tertullian, for he not only responded to early false teaching, but he worked out much of the language we use to speak about the Trinity.

Even though he was a lawyer (or maybe being a lawyer helped) Tertullian provided a fantastic response to a man called Praxeus. Praxeus so stressed the unity of God that he denied that God exists in three persons. Instead, Praxeus said, God wears three masks: sometimes he wears the Father mask, sometimes he puts on the Son mask, and sometimes he wears the Spirit mask. So the one God has three modes, or ways, of presenting himself: the Father mode, the Son mode, and the Spirit mode. Praxeus taught a form of modalism. He blurred the distinctions between the persons in the Trinity.

If we believe Praxeus, the Father became his own Son, and the Father suffered and died on the cross (patripassianism). But if the whole of God died on the cross, then Nietzsche was right when he declared that God is dead. If whole of God died on the cross, there can be no resurrection, for which god can raise the real God from the dead? Who was Jesus talking to when he said, ‘Father, into your hands I commit my spirit’ (Lk 23:46)?

Tertullian’s response was an appeal to Scripture. He argued that the Father, Son and Holy Spirit are not the names of masks worn by God, rather they represent real, eternal distinctions. The Father was not born of a virgin. The Father did not die on the cross. The Father did not walk away from the tomb. Tertullian argued that the persons with the Trinity should not be blurred, rather within the unity of God there is diversity.

As he pondered the nature of God, Tertullian thought up the word ‘Trinity’. He coined the word as a way of expressing the Bible’s teaching that God is three-in-one. The word has crept into and remained in our theological vocabulary. The fact that the word ‘Trinity’ sounds ordinary to our ears is testifies to the fact that no-one since Tertullian has thought up a better word to summarise the three-in-oneness of God.

Tertullian also brought into habit the word ‘person’ to refer to the Father, the Son and the Spirit. The Father is a person, the Son is person, and the Spirit is a person. Tertullian used the word ‘person’ to refer to a concrete individual. Each person in the Trinity is an individual, but not so individual that there are three separate divine beings. The word ‘person’ also reminds us that the Father, the Son and the Holy Spirit are not objects or things. They are persons: they can be praised and thanked, they can be loved and they are capable of loving one another.

Then Tertullian introduced the word ‘substance’. While he speaks about the three separate persons of the Trinity, at the same time they exist in one divine substance. The Father and Son are distinct yet they belong to the one divine being. The Holy Spirit belongs to the substance of the divine being. Unity in diversity means one substance in three persons.

We owe a lot to Tertullian who corrected modalism and gave us some useful language to express the self-revelation of God in three persons. However, his understanding was not without its weaknesses, and so men like Athanasius, John of Damascus and John Calvin came afterwards and they make a vital contribution. But we must leave the study of these men to another day.

Should we not stop and ask whether or not all this doctrine has really taken us anywhere? Can’t we just come to church and love each other? Can’t we just share together? Can’t we just serve each other? Can’t we just sing? Can’t we just….? If you think you can live this way, then you’ve missed the verse, ‘watch your life and doctrine closely’ (1 Tim 4:16). Your doctrine determines the quality of your life. Life and doctrine are twisted together like strands on a rope. So do the hard work, watch your doctrine, come to terms with the Trinity.

You know the great thing about a trinitarian life? It’s trinitarian. I’ve been saved by God who sent the Son into the world to die for my sins and he rose and the promise is that I will rise to be with him. Jesus brings us back into loving relationship with God who is the source of all love and life. This is no life apart from connection to the Trinity. And where does the Holy Spirit reside? In me. Now I am in relationship with the Trinity.

So now all of my life in trinitarian. All of my work is trinitarian. All of my prayer, all of my service. All of my ministry is by the Spirit, through the Son, to the Father. That’s all of life. The Spirit within me empowers me to live the trinitarian life, through the Son and to the glory of the Father.

The second thing to say about the trinitarian life is this: it is a loving life. Unless you know who love is, unless you know where love comes from, unless you know what love is, then how do you intend to love? Love is not sleeping with your girlfriend or boyfriend. It’s not forgetting your marriage vows. It’s not abusing your wife and deflating your husband. It’s not cheating in the workplace. It’s not lying to save your own skin. That’s not trinitarian love because trinitarian love is other centred love, its love that acts for the well-being of the other person.

The early Church Fathers had a little word called ‘perichoresis’. They used this word to describe a wonderful thing. It’s a word that paints a picture of each person in the Trinity dancing in harmony with the other persons. There is perfect harmony within the Trinity because within each divine person there contains the whole of God. The Father is still the Father, the Son is still the Son, the Spirit is still the Spirit. But since all three are fully God the whole of God lives in each of the three persons without blurring the distinctions.

The early Church Fathers used this word to say that Christians are able to dance with God. That we are able to enter into the harmony that exists within the Trinity. Amazingly, God invites us to enter into the trinitarian life and share the joy of the trinitarian life.

Indeed, the invitation to share the trinitarian life is an invitation to leave behind the homelessness of this world. In this life we are exiles, displaced and uprooted, living away from our heavenly home. We have been invited to a better country, a land without sin and where our triune God dwells amongst his people—we are invited into a city which does not need the sun or the moon to shine on it, for the glory of the Lord gives it light.

So we say along with the heavenly realm, ‘Holy, holy, holy is the Lord Almighty, who was, and is, and is to come’ (Rev 4:8).