What if it's true, after all?

Libby Purves on the threat that Christmas poses to comfortable agnosticism

SO THERE'S a crib in the off-licence, and a star of Bethlehem in the bookie's window. At this time of year religious symbols invade everyday secular life like trailing ivy pushing though the cracked window of our uncertainty. The girl at the Card-Aid stand confides that for every card with a comic Santa or neutral holly, she sells six with steeples and cribs and Virgins. From icons to Renaissance madonnas, fine art gives a fine excuse; from the rationalist's mantelpiece from now to New Year there will shine clouds of irrational glory, the ancient eyes of the mystic and the praying hands of angels.

Christmas is an uneasy, defiant time for the comfortable agnosticism of common British life. Some fudge it, and sing the carols for nostalgia and catharsis; more determined unbelievers prate about "cultural resonance" when caught sniffing sentimentally over a child with tea-towel and stuffed sheep beside the playgroup manger. Perhaps one day the religious symbols will fade entirely and we shall be left only with tinsel and ribbon and garish orange bulbs across Oxford Street proclaiming " 'Tis the season to be Tango'd". That time has not come yet. Christmas still spooks the secular society with a huge, restless question.

John Betjeman, teddy bear to the nation, asked it in a Christmas poem 40 years ago. Amid eight verses of lamplight and country churches and town hall bunting, he suddenly asks:

And is it true? And is it true,

This most tremendous tale of all...

The Maker of the stars and sea

Become a child on earth for me?

If it is true, concludes this arch poet of traditional appearances, then none of the trappings count at all. "No carolling in frosty air, / Nor all the steeple-shaking bells / Can with this single Truth compare..."

It is, for all its dog-eared cosiness, a disturbing poem. You can hear a nervous prattle rising to drown the question. "Is it true? Well, there's different kinds of truth - now darling, leave the brandy butter...just hold the tree steady while I do the fairy. It's a symbol, you see. Of - er - new life. And families. And being nice to one another..."

At the other extreme, a dour and godly minority bitterly resents the sentimental religiosity of the season. They look at the off-licence crib in the same spirit that Stella Gibbons beautifully evoked when Mr Mybug quoted her heroine's favourite writer: "It is like seeing a drunken stranger wrapped in your dressing gown." The God-pros, clerics and evangelists, stifle this irritation and put a good face on this usurpation of their symbols by using the annual explosion of mangers and angels to bang home their message from the pulpit, and hit the flustered radio listener with dubious pieces of information about mince pies representing Christ's manger.

But always there is a tension behind a Christian festival in an increasingly post-Christian age: "And is it true? And is it true?" It cannot be resolved by a packet of cherub table-napkins and a chorus of "Little Donkey".

The real question is how far, and for how long, a society that rejects Christianity can continue to benefit from its social and moral legacy. However justly humanists may point to the warts that disfigure that legacy, there is far more to it than warts. Our very law stands on Old Testament teaching on duty to one's neighbour. Our parliament, educational ideals, respect for literacy, and notion of just war have grown up through a Christian millennium. Biblical strictures against oppressing the poor came long before Karl Marx's; the doctrine of forgiveness and redemption long pre- dates counselling and therapy. From sexuality to railway station architecture, from nonconformist austerity to the floral shrines to accident victims, Christianity has left indelible footprints on the way we think, and the way we are. It thrums through our prose and music; tags from Proverbs and Ecclesiastes and the 1660 Prayer Book turn up in book titles and comedy skits, and no pop composer seems to feel accepted until he has done a requiem.

But if it is just "heritage", or a branch of cultural studies; if it is empty of belief in a real God and a real overarching law, will it not inevitably fade? Or become fragmented into a gabble of superstition and disconnected decadence? You can already see this happening. Drop into an "occult shop" in, say, Glastonbury, and amid the jumble of earth- gods and green men and Wicca symbols and chipped buddhas and black candles and crystals you will inevitably find Christian oddments: a plaster statue of St Teresa of Lisieux, a dog-eared Testament, a crucifix, a bust of Pope Pius XII. Ask the bearded lunatic behind the counter what on earth these things are doing here, and he will say, with vague piety, that they "have power". Nobody prosecutes them for blasphemy. Nobody - for fear of being labelled a fanatic - ventures to say that there is a difference between Christian symbols with 2,000 years of codified belief behind them, and bits of tortured wire with rock- crystal wedged in the middle. That would be "judgemental".

If Christian belief erodes from the core, the tinselly symbols left standing will eventually collapse into this rubble. Should we care? Does it matter that I saw a crib scene in a toy shop the other day with a Teletubby in the manger? Is this harmless cultural change, or terminal decadence?

You could argue for complacency. Atheists often point out sternly that it is perfectly possible to be a moral and ethical person without religious belief; and so it is. My father (owing to a Scottish Presbyterian childhood) was ferociously against religion, yet remained the most high-principled of men. However, it can be argued that the principles he lived by were set by ten centuries of Christian culture, and that he was thus an unconscious beneficiary, ethically speaking, of the Ten Commandments. It could also be argued that if he were born today in England, he might not get that legacy. And while an atheist may be a thoughtful moralist, it strikes me that for the great workaday mass of us it has traditionally been easier to have at least a rough religious structure for virtue. Christianity has many conveniences: it combines humility and a sense of sin with confidence in redemption and heaven. It places love of one's fellow-human at the centre - not tolerance, not justice or tribal loyalty, but Love. It forbids hypocrisy. It has a wonderfully tough resistance to political hijackers. As Dean Inge said, it is a revolutionary idealism which estranges revolutionaries by its idealism and conservatives by its drastic revaluation of earthly goods. There is a lot to be said for it.

I think it is an awareness of this which makes us so fretful about the jolly hypocrisies of the Christmas season. The fretfulness leads us up strange paths: there is a school of thought, best represented by the philosopher Roger Scruton, which is so worried about the cultural impoverishment that a loss of Christianity brings that its adherents are all for shoring up the empty walls, and living consciously by "God's law" even though they do not believe in God. This - if I understand the argument correctly - is weird. It must be the first instance of throwing out the baby and keeping the bathwater. A while ago I wrote, in the context of my own rebellious teenage years, a cheeky critique of the more atavistic admirers of the late Monsignor Alfred Gilbey, who was famous for his gaiters and frock- coat and dislike of change, women students, etc.

Among strong letters from both sides, I had one extraordinary communication from a man now in his forties who, though a non-believer, revered Gilbey's theology and life because he stood "above all, for stability". But without dynamic belief at its core, what is stability? Fossilisation, fear in aspic. Cling to empty symbols and you become Miss Havisham, or one of those worrying people who put out food every night for long-dead pets and try not to notice themselves throwing it away in the morning.

Betjeman was right to make us ask the awkward question: And is it true, and is it true? And if it is not, why do the church bells stir us so?

Libby Purves's 'Holy Smoke' is published by Hodder & Stoughton at pounds 14.99.