The National Gallery's exhibition "Seeing Salvation: the image of Christ" will make only the determinedly irreligious uncomfortable. It is not a crafty manoeuvre by the National Gallery and the Jerusalem and Pilgrim Trusts aimed at gaining Christian converts. It is an attempt, and a successful one, to show how artists from the third to the 20th centuries have approached the problem of depicting Christ - someone whose life and death has helped to form the culture and the civilisation of the last two millennia, of which, believers or not, we are all the inheritors.
Every visitor will find his favourite exhibit. I was immediately entranced by the little fifth- century Roman oil lamp, with its Chi-Rho symbol for Christ fashioned on one end of the lamp. When the candle was lit, the shadow of that sign flickered on the wall behind. Holman Hunt's The Light of the World, in the same room, has been borrowed from St Paul's Cathedral. It was immensely popular in the 19th century, but is a little too placid for me. Christ has the resigned air of a wartime Englishman waiting for the last bus in the blackout.
Far from placid is the Adoration of the Kings painted by Breughel the Elder in 1564. The child Jesus in his mother's arms looks understandably scared to death. Nasty kings, belligerent soldiers and greedy-looking yokels push forward with more interest in the gifts than the child. It is well matched by Hieronymus Bosch's The Crowning with Thorns. Christ gazes at us in calm resignation, while four villains set about ramming the crown of thorns on to his head.
One group of pictures illustrates how artists have attempted to portray "The True Likeness" of Christ - not that they had any evidence to go on. Nevertheless, the legend of the image of Christ's face on the towel with which Veronica wiped him is a strong one. Whatever its origin, none of those images compares with the dignity of the mysterious face on the Turin Shroud.
From the Netherlands comes an impressive 15th-century statue of the naked Christ, sitting on a pile of rocks, head in hand and crowned with thorns. Anyone who has known a moment when it is clear that life can only get worse will feel right at home here. Among the post-crucifixion paintings, I spent some time with Bernardo Strozzi's The Incredulity of St Thomas. Doubting Thomas is someone with whom most honest Christians can identify. Here, Strozzi makes even Christ look rather surprised when Thomas tentatively touches the wound in his side.
The last of the exhibition's seven themes is "The Abiding Presence". The room is dominated by Salvador Dali's Christ of St John of the Cross and Stanley Spencer's The Resurrection, Cookham. Spencer's Resurrection is a calm, casual, sunshiny affair. The villagers of Cookham are in no hurry to get up and get going. The joy of tomorrow has started today. Dali's, by any standard, is a most powerful work - "My principal preoccupation was that my Christ would be as beautiful as the God He is." Bought by the Glasgow Art Gallery in 1952 for £8,200, it has been controversial ever since.
Finally, there is a photograph of Mark Wallinger's Ecce Homo, a statue of the young Christ which briefly occupied the north-east plinth in Trafalgar Square. Sir Roy Strong thought it, in that context, "glaringly inappropriate". I think he is quite wrong. For a few weeks, a helpless young Christ looked out over a square that, from Nelson downwards, is dominated by power and militarism. One small gesture of counterbalance was not a bad idea.
Crowds wandered through the exhibition on both the afternoons when I visited. Many stayed to watch the short accompanying film. Few could have left disappointed. "Who do men say that I am?" Christ once asked his apostles. Generations of artists in their different ways have tried to answer that question, and this exhibition is a tribute to them.
It is impossible to be comprehensive, but I regretted the absence of one version of Christ: as a challenge to the social order. Eric Gill's wonderful carving of Christ driving the money-changers out of the temple, for instance, is not included. Gill's money-changers were the profiteers of the first world war, and his interpretation was not much appreciated by those in Leeds who commissioned it. Someone must have painted Christ facing the fury of the rich, or the indignation of the high priests. Some of Fritz Eichenberg's woodcuts of Christ among the poor, or Arthur Wragg's angry drawings of the 1930s with his theme "Jesus Wept", might have had a place here. Perhaps Christ, the Comforter of the Disturbed, is still rather more acceptable than Christ, the Disturber of the Comfortable.
"Seeing Salvation: the image of Christ" is at the National Gallery in London until 7 May
"Seeing Salvation", a four-part series presented by Neil MacGregor, will be transmitted on BBC2's Art Zone from Sunday 2 April
Bruce Kent is president of the National Peace Council