Scrupulous, sceptical historians have raked and raked over the gospels for 200 years. First came the picture of Jesus as a good, liberal European. Then came Albert Schweitzer (yes, he of Bach and Lambarene fame). Schweitzer saw that the early lives of Jesus were written by people who looked down the long well of history and saw their own face reflected at the bottom. He realised that the world of the New Testament is strange, even alien to us, because dominated by eschatology, namely the belief that creation had come to its climax, that the end of all things was near. Amid all the changes and scholarly fashions since then, this fundamental insight has remained.
After Schweitzer, and particularly in the middle years of this century, scholars doubted whether we could know anything about the historical Jesus for certain, except that he lived and died. All that mattered was an existential encounter of faith. More recently, however, there has been a growing consensus that some things at least can be known with as much certainty as any other historical event.
First, that Jesus was a Jew who needs to be seen in the context of his time. He was a teacher and Galilean healer. Secondly, he proclaimed the beginning of God's long-expected transformation of human affairs (the Kingdom of God). Thirdly, he gathered around him a small group of companions who were to form the nucleus of the ingathering of the people of God in the new age that was about to dawn. Fourthly, he went out of his way to mix with and eat with those whom society as a whole marginalised. In doing this he taught that he was simply acting out God's search for the lost. Fifthly, he felt the tremors of his forthcoming death and interpreted it as a self-offering to bring in this realm of love.
Some would want to go much further than this minimalist account. Indeed historians of secular history often accuse New Testament scholars of being too severe and sceptical in their canons of truth.
What we also know is that the Christian movement got going in history on the basis that God had raised Jesus from the dead, thereby vindicating both him and his message. Christians believed that in some decisive sense the new age had indeed been inaugurated, not for the world as a whole to see but in the intimate relationship of Jesus to the one he called Father and the extension of this in the communal lives of those who followed his way of love and were filled by his spirit.
What still remains as the great mystery is what actually happened between the death of Jesus and the conviction of his first followers that he had been raised to a universal contemporaneity. Evidence can be adduced in favour of this belief but here, more than anywhere, we are in the realm of faith: faith which will be formed - or lost - partly in response to the picture of Jesus presented by the gospels, partly by our experience of the Christian community and our own spiritual insights, and partly by our whole understanding of what God might or might not be like.
The gospels are not biography and every line of them is written upon the assumption that the one described in them is the agent of human salvation, raised from the dead and through his spirit living in his followers. They contain legend, myth, poetry, sublime teaching and stories of amazing happenings as well as more humdrum "facts". From all this, the picture emerges of a man with a mission from the one he called "Abba, father", to whom he related intimately and with total trust and who calls into question most of the values by which we live: the pursuit of power, prestige, money, fame and pleasure.
In his teaching he literally turns the world upside down, for the first will be last and the last first. By these standards all will be judged. The message is totally uncompromising. It is easier for a camel to go through the eye of a needle than for a rich man to enter the Kingdom of God.
Does it matter that any of this was actually said and done, that what the gospels record as happening did happen? Perhaps it does not matter whether or not Lazarus was raised from the dead because the fourth gospel tells that story in order to enact the truth "I am the resurrection and the life"; that Jesus can raise us from both physical death and the spiritual death of self-absorption. Perhaps it does not matter whether or not Mary actually said "Behold the handmaid of the Lord. Be it unto me according to thy will" because such receptivity and loving response to divine grace is fundamental to the whole Christian life, of which Mary is an archetype.
Perhaps it does not even matter whether the three kings, the shepherds and the angels actually gathered around the crib of the Christ child. What does matter is the claim that God himself has taken our humanity; that he encounters us in this particular person, living at a particular time in a particular culture.
From a Christian standpoint, God is not a puppeteer pulling and pushing the strings of human existence. He has chosen to change human life from the inside, by entering the flux of history and putting himself at the mercy of events. This includes putting himself at the mercy of historians and all of us in every generation who have to interpret and evaluate those events.
Some of the gospels can be responded to as moral and spiritual truth, setting light to the question of historical fact. But there are some foundational events whose claim to historical truth cannot be fudged. We might wish it were otherwise; but it makes a crucial difference, whether or not those foundational events occurred.
The author is the Bishop of Oxford