All Christian denominations believe that Jesus Christ is God. If they do not hold to the orthodox teaching of the Trinity and the incarnation (God the Son becoming the man Jesus Christ), then they are not truly Christian.

The Doctrine of the Trinity

The doctrine of the Trinity, that God is ‘one God in three persons’, is absolutely fundamental and has been the Christian understanding of God since the earliest days of the church. One of the earliest Christian creeds attributed to a 4th Century Bishop of Alexandria called Athanasius defines the Trinity. It’s a complex statement, so read it through and then we will draw out the key components. (It’s worth noting that when he says ‘catholic’ he is using the term in it’s traditional meaning of ‘universal’ – not of the Roman Catholic Church as it is today)

The Athanasian Creed

And the catholic faith is this: That we worship one God in Trinity, and Trinity in Unity; Neither confounding the Persons; nor dividing the Essence. For there is one Person of the Father; another of the Son; and another of the Holy Ghost. But the Godhead of the Father, of the Son, and of the Holy Ghost, is all one; the Glory equal, the Majesty coeternal. Such as the Father is; such is the Son; and such is the Holy Ghost. The Father uncreated; the Son uncreated; and the Holy Ghost uncreated. The Father unlimited; the Son unlimited; and the Holy Ghost unlimited. The Father eternal; the Son eternal; and the Holy Ghost eternal. And yet they are not three eternals; but one eternal. As also there are not three uncreated; nor three infinites, but one uncreated; and one infinite. So likewise the Father is Almighty; the Son Almighty; and the Holy Ghost Almighty. And yet they are not three Almighties; but one Almighty. So the Father is God; the Son is God; and the Holy Ghost is God. And yet they are not three Gods; but one God. So likewise the Father is Lord; the Son Lord; and the Holy Ghost Lord. And yet not three Lords; but one Lord. For like as we are compelled by the Christian verity; to acknowledge every Person by himself to be God and Lord; So are we forbidden by the catholic religion; to say, There are three Gods, or three Lords. The Father is made of none; neither created, nor begotten. The Son is of the Father alone; not made, nor created; but begotten. The Holy Ghost is of the Father and of the Son; neither made, nor created, nor begotten; but proceeding. So there is one Father, not three Fathers; one Son, not three Sons; one Holy Ghost, not three Holy Ghosts. And in this Trinity none is before, or after another; none is greater, or less than another. But the whole three Persons are coeternal, and coequal. So that in all things, as aforesaid; the Unity in Trinity, and the Trinity in Unity, is to be worshipped. He therefore that will be saved, let him thus think of the Trinity. He is essentially saying that God is ‘one God in three persons’, that God is Father, Son, and Holy Spirit, persons who are distinct from each other, but are all equally God and are united. We cannot separate them out into three different deities, nor can we fuse them into one. We have to hold these truths in tension. To summarise, here are three statements which declare the orthodox Christian belief about the Trinity: 1.      There is one God2.      He is three distinct persons – Father, Son and Holy Spirit.3.      They Father, Son and Spirit are all equally God A common objection to this doctrine is that the word 'Trinity' is not in the Bible, so therefore it is not ‘biblical’. It is true that the term ‘Trinity’ is not in the Bible, but the truth of this doctrine is throughout the Scriptures. This begins in Genesis 1:2, where we see that the Spirit of God hovers over the waters at the creation of the world, and continues in Genesis 1:26-27, where God uses the plural terms ‘us’ and ‘our’ to describe himself: “26 Then God said, ‘Let us make mankind in our image, in our likeness, so that they may rule over the fish in the sea and the birds in the sky, over the livestock and all the wild animals, and over all the creatures that move along the ground.’ 27 So God created mankind in his own image, in the image of God he created them; male and female he created them.” Throughout the Old Testament the Bible regularly points to the fact that God is triune, but it isn’t until the New Testament that this comes into sharp focus as God the Son enters the world to be born as the man Jesus Christ. This is called the incarnation. 

The Doctrine of the Incarnation

The second person of the Trinity, God the Son, took human form in the man Jesus Christ. Jesus was both fully man and fully God. He became a human being in order to reveal to other human beings exactly what God was like (Hebrews 1:1-3), and to save us from our sins by dying on the cross (Matthew 1:21). Matthew’s Gospel teaches us this very clearly. God the Holy Spirit causes Mary to conceive the child (Matthew 1:18) and Matthew explicitly declares that Jesus is God himself come to earth, a fulfilment of something that God had promised in the Old Testament: “22 All this took place to fulfil what the Lord had said through the prophet: 23 ‘The virgin will conceive and give birth to a son, and they will call him Immanuel’ (which means ‘God with us’).” Matthew 1:22-23. Jesus’ identity as God the Son, and the Trinitarian nature of God comes through in many other places in Matthew’s Gospel and the rest of the New Testament too. Matthew 3:16-17 is a prime example: 16 As soon as Jesus was baptised, he went up out of the water. At that moment heaven was opened, and he saw the Spirit of God descending like a dove and alighting on him. 17 And a voice from heaven said, ‘This is my Son, whom I love; with him I am well pleased.’ Other passages which speak clearly on the Trinity and the Incarnation are Matthew 28:16-20, John 1:1-18, Philippians 2:5-11, Colossians 1:15-23, and these passages make clear that God the Son died on the cross in order that we might be saved from sin and death if we trust in Him. 

But why does this matter?

The Athanasian creed might help us again. It goes on to say:Furthermore it is necessary to everlasting salvation; that he also believe faithfully the Incarnation of our Lord Jesus Christ. For the right Faith is, that we believe and confess; that our Lord Jesus Christ, the Son of God, is God and Man; God, of the Essence of the Father; begotten before the worlds; and Man, of the Essence of his Mother, born in the world. Perfect God; and perfect Man, of a reasonable soul and human flesh subsisting. It is necessary to everlasting salvation to believe that God the Son is incarnate in the person of Jesus Christ. Someone who does not believe that Jesus was God cannot be saved. Jesus himself was very clear about this and says so in John 5:16-27:16 So, because Jesus was doing these things on the Sabbath, the Jewish leaders began to persecute him. 17 In his defence Jesus said to them, ‘My Father is always at his work to this very day, and I too am working.’ 18 For this reason they tried all the more to kill him; not only was he breaking the Sabbath, but he was even calling God his own Father, making himself equal with God. 19 Jesus gave them this answer: ‘Very truly I tell you, the Son can do nothing by himself; he can do only what he sees his Father doing, because whatever the Father does the Son also does. 20 For the Father loves the Son and shows him all he does. Yes, and he will show him even greater works than these, so that you will be amazed. 21 For just as the Father raises the dead and gives them life, even so the Son gives life to whom he is pleased to give it. 22 Moreover, the Father judges no one, but has entrusted all judgment to the Son, 23 that all may honour the Son just as they honour the Father. Whoever does not honour the Son does not honour the Father, who sent him. 24 ‘Very truly I tell you, whoever hears my word and believes him who sent me has eternal life and will not be judged but has crossed over from death to life. 25 Very truly I tell you, a time is coming and has now come when the dead will hear the voice of the Son of God and those who hear will live. 26 For as the Father has life in himself, so he has granted the Son also to have life in himself. 27 And he has given him authority to judge because he is the Son of Man. The Jewish leaders knew that Jesus was equating himself with God the Father, and this was abhorrent to them, they wanted to kill him for his claim to be God. Jesus doesn’t deny this, in fact he says that only those that except the truth that He and the Father are equal and united, he who honours the Son as he honours the Father (v23) can have the gift of eternal life and be rescued from God’s judgement (v24). These are important words, with big consequences, and you need to consider seriously where you stand on this issue. It isn’t just a matter of intellectual understanding, but is literally a life and death issue.