Katy Guest: We wish you a merry Solstice. Or whatever...

Light of the world or warmth in the gloom? Our writer on Pagans

The next time two smartly dressed young people knock at your door, keep you chatting as if they're casing the joint and then ask you whether you really understand the true meaning of Christmas, try this: invite them in, brew up some hot mead, and explain to them patiently about a time 2,000 years ago when early Christians went in search of an arbitrary date on which to celebrate an event of middling theological importance in their fledgling religion.

Sitting around a festive Yule tree (redolent of the Norse god Ullr), decorated in tiny, glittering symbols of the end of darkness and the return to light, watch their little faces light up as you share seasonal offerings of meat and sprouts, in communion with the seasonal generosity of nature. Soon they will understand the true meaning of the Winter Solstice.

It's not that the Romans stole Pagan traditions, exactly, when they reached these shores aiming to convert Britannia to their new religion and decided to celebrate the birth of Christ during the festival of Mithras, the Roman god of light.

Christmas happens on 25 December all over the world, of course. But, in other Christian countries, Christmas Day is not the most important event in the calendar. We go large on Christmas here because it is precisely the time of year when people in northern Europe need to party. Before telescopes, before literacy, before even clocks, it would take a few days for early Pagans to notice that the days had started getting longer and that Yule had given birth to the child of promise so that the Wheel of the Year could start its revolution again. And so, four days after the Winter Solstice, we celebrate – more or less exactly as we always did, as far as we can tell.

It seems weird, then, that there is still so much fear and ignorance about relatively benign Pagan traditions in this country. This month the Daily Mail, where fear and ignorance are almost a religion in themselves, described how Pagan prisoners will be given time off their duties to celebrate up to four festivals a year. The paper was sad to have to reveal that Pagans eat eggs and Simnel cake on the Spring Equinox and roast goose at the Autumn Equinox, and that on Samhain ("celebrated on Halloween") these degenerate people actually go apple bobbing. Where will the depravity end?

Of course, Paganism, like Christianity, comprises many different religions: Wicca and Witchcraft, Druidry, Heathenry, Shamanism... And what will really frighten the Daily Mail is that Paganism is growing. The historian Ronald Hutton made the only serious study of numbers in 2000, when he estimated that about 120,000 people attended Pagan rituals and meetings. He now accepts that the number is about twice that, and the Pagan Federation believes it to be closer to 360,000, which would be more than the official number of Sikhs in Britain recorded by the 2001 census.

Add to that the environmentalists for whom humans' link to the earth is vital, and the number must be in the millions. Add to those everybody who has a Christmas tree, or decorates the house with twinkly lights, and Pagans pretty much have it sewn up. I'm not a Pagan, but I do believe many of their scary fundamentalist doctrines: that the sun rises and sets each day; that summer is lighter than winter; that lots of food is available in autumn; and that life is generally better when it's light and warm and there are roast potatoes cooked in goose fat.

It's not that I'd encourage anyone to demonise instead people who believe that a man was born of a virgin, died and then rose again to teach us all to hate gays; my personal creed is more tolerant than that. But I will be celebrating the Winter Solstice this week. Or do I mean Christmas? It's hard to tell.