Tonight, lots of people who rarely go to church will crowd into Watchnight services up and down the country. Some will come from parties and pubs, and the air will be redolent of alcohol fumes. There might be some hilarity in church, and even a wee spot of vomiting. And that's just the minister. As worshippers sing the Christmas carols, long-forgotten memories will come flooding back - of school carol services, of punches traded with siblings as presents were unwrapped, of more innocent times, of family life fractured by divorce or bereavement. Tears will be shed. The congregations will be made up of believers, half-believers and non-believers.

It's just possible that there will be some Muslims present, seeking to explore what it means to be a Christian. Channel 4's series Make Me a Muslim, which finished last week, raised some interesting questions. Seven people from Harrogate were invited to explore the teachings and practices of Islam for three weeks. It proved to be a culture shock - no booze, no pork, no scanties, prayer five times a day, alms to the poor.

The programme itself was a mixed bag. The participants themselves seem to have been chosen mainly for their freakishness - how is it that so many TV programmes these days seem to morph into Big Brother? - and they sometimes represented the boorish individual excesses of Friday-night Britain. Islamic restraint, modesty and insistence on the primacy of the spiritual did not go down well; yet each person was affected in unexpected ways. Phil, an impetuous taxi driver who had been vocal about Muslim rigidity and who sloped off to eat sausages and visit a lap-dancing club, ended with a respect for Islam. What changed him was the experience of working for a day in a shop owned by a Muslim, and talking with a young Muslim who was serving in the British Army. Despite the programme's limitations, there were challenges to stereotypes and prejudices, and minds and hearts were influenced, if not entirely changed.

The hardest question for us as a species is how we are to live with each other - and with the planet itself - on this fragile earth. Politicians are too obsessed with their prospects at the next election to seriously engage with the long-term process of change that is needed. How are we to understand the culture of others, particularly those who may be living in the same street or town?

Phil's outlook on life was as rigid as any religious dogmatist; until he met and conversed with real, live Muslims, he was ignorant of the beliefs, virtues and insights of people living not far from his own front door. Even in a small country such as Scotland, there are Protestant Christians who have minimal understanding of what it means to be a practising Roman Catholic Christian, and vice versa - never mind an informed knowledge of other faiths.

I would like to see churches, mosques and synagogues in Scotland embark on a process of mutual hospitality and learning, in which participants are invited to "get inside" each others' faith tradition. Religions are as much about practices as beliefs; worship, prayer, reflection on sacred texts, charity and work for justice do not depend on rock-solid personal belief systems.

Text books fail to get to the heart of what it means to be a Christian or a Muslim. Nothing beats personal encounter. I would like to see Richard Dawkins spend a month with a Christian family in Easterhouse, and Rowan Williams spend a similar time with the finest atheists in the country.

There could be national conversations at places such as Iona and Scottish Churches House in Dunblane. These exchanges should be extended way beyond religion, to the spheres of politics and culture. Scotland could come alive with such open, vigorous and hospitable interchanges. To facilitate the process, I would recommend two brilliant classics by that wonderful polymath Theodore Zeldin - An Intimate History of Humanity and Conversation: How Talk Can Change Our Lives. The point would not be to convert other people - though if it were a truly open process it might sometimes produce that outcome - but to dispel ignorance and generate understanding. It would also result in a greater appreciation of one's own tradition. One could guarantee that few lives would be unaffected.

Lowest-common-denominator mish-mash is not what is required. Stuff politically-correct Winterval. Celebrate your own tradition, and participate with an open mind in the festivals of others. If you make your way to a Watchnight service, showing at a church near you, you'll find that the air will be filled not just with alcohol fumes but with yearning. For us meaning-seeking humans, it's good to be open to spirits of various kinds.

The season's peace and goodwill to all may even turn out to be catching.