Many of our colleagues are sceptical of the miraculous elements in the life of Jesus Christ: the virgin birth, the healing miracles and the resurrection. They 'know' as health professionals that such things are medically impossible.

But the real miracle, on which all rests, and which we celebrate at Christmas, is actually the incarnation, the Word becoming flesh. (1) CS Lewis, in his classic book Miracles, calls it 'the grand miracle'. (2)

If we can accept the incarnation - the idea that God could become a human being - then all other aspects of Jesus' life naturally follow on. They are exactly what we would expect if God were walking on the earth. Apologist Josh McDowell has suggested that if God became a man we would expect to see the following things: (3)

He would have an unusual entry into life - which is exactly what we find in the virgin birth.

He would be morally perfect. When Jesus challenged others to find him guilty of sin no one could answer. (4)

If God became a man, we'd expect him to perform astounding miracles. The gospel accounts are full of them: he heals those who are deaf, blind and paralysed; he calms storms, walks on water and turns water into wine. According to eyewitnesses, Jesus healed diseases for which even today there is no treatment; instantaneously, irreversibly and unambiguously.

We'd expect him to speak the greatest words ever spoken. People responded to Jesus in amazement. 'How did this man get such learning without having been taught?' (5) 'No one ever spoke the way this man does'. (6)

Psychiatrist James Fisher has written: 'If you were to take the sum total of all the authoritative articles ever written by the most qualified of psychologists and psychiatrists on the subject of mental hygiene - if you were to combine them and refine them and cleave out all the excess verbiage - if you were to have these unadulterated bits of pure scientific knowledge concisely expressed by the most capable of living poets, you would have an awkward and incomplete summation of the Sermon on the Mount'. (7)

If God became a man, we would expect him to have a lasting and universal influence. Why is it that all religions try to accommodate Jesus somehow, to find a place for him? In the words of historian Kenneth Latourette, it is simply because 'measured by his effect on history, Jesus is the most influential life ever lived', (8) profoundly shaping our worldview, our laws, our history, our culture.

We would expect him to satisfy the spiritual hunger in man. Millions testify that Jesus Christ has filled the spiritual vacuum in their lives; that his promise that those who come to him will not thirst or hunger is amazingly true. (9)

Finally, if God became a man, we would expect him to exercise power over death. The resurrection of Jesus Christ is the best attested historical fact in all of antiquity; over 500 witnesses to his rising from the dead. (10) It is the only logical explanation for the empty tomb, the dramatic change in the disciples and the spread of the early church. But what does the incarnation mean for us personally?

First, it reminds us that Jesus understands us. He knows what it is like to be a human being. He knows hunger and thirst, pain and sorrow, bereavement and loss, rejection and betrayal. As the writer of Hebrews tells us, he can sympathise with our weaknesses because he has been tempted in every way as we are, and much more. (11)

Second, it reminds us that Jesus can help us: 'because he himself suffered when he was tempted, he is able to help those who are being tempted'. (12) What are our areas of weakness? What do we despair over? What is it that is stopping us growing as Christians? What is it we are fighting that perhaps no one else sees or knows about? He is able to help us.

Third, the incarnation is a model for us in our own Christian lives. We are called to walk in Jesus' footsteps. The cross is a pattern for us to follow. We are to carry the cross, (13) to take our share of suffering, (14) to bear the burdens of others. (15)

Fourth, the incarnation helps us in our evangelism. It challenges us to cross social barriers as Jesus did, to make ourselves accessible and vulnerable, in the way that Jesus was, to be, in the words of Paul, 'all things to all people'. (16)

But finally, and most importantly, the incarnation reminds us of why Jesus came, because Christmas is the prelude to Easter. The same Jesus who grew in the womb and lay in the manger was sent to die on a cross and rise from the dead in order to reconcile us to God. (17)

Christmas starts and ends with Jesus Christ. Let's keep him at the centre.

Peter Saunders is CMF Chief Executive.