am writing this on Good Friday, one of the holiest days in the Christian calendar. It was once the only day in the year, apart from Christmas, when national newspapers didn’t publish. All shops were closed, and a reverent hush descended on the land. Now, though Good Friday is still a holiday, it is ignored by many businesses. The absence of horseracing is about the only reminder that this day is different from any other.

A significant proportion of the population (and I don’t mean Muslims) couldn’t explain what it is supposed to commemorate. Lots of people wish you “happy Good Friday”, which seems to me to miss the point.

Yet in a country that is more secular than ever we have a government determined to introduce more faith schools. As the union conferences have shown over the past week or so, many teachers react with incredulity and horror. But ministers insist faith schools are what parents want, and they appear to be right.

Why? Parents think faith schools deliver better academic results and better discipline. Since no one ever claimed that religion makes you more clever, we must assume the faith schools’ X factor is the discipline and the improved results follow better behaviour. It is, after all, a truism that religion makes you a more moral person.

Like many truisms, it’s wrong. As I have argued here before, religion has a magnificent record of inspiring art, architecture, music, literature and even scientific inquiry. It has completely failed to improve human behaviour. Rather, it tends to persuade people that, provided they are believers, they can get away with anything. This may explain why several Christian sponsors of city academies come from what most of us would regard (without implying any actual dishonesty) as slightly dodgy occupations. At least two are car dealers, hardly a trade noted for its ethical standards.

I accept that religion may have a certain calming effect on children. Now socialism is deemed to have failed, religions provide the only belief systems that accept the equal worth of every human being, though they tend to reintroduce inequality by relegating unbelievers.

That must be a comfort to children of low self-esteem, if they ever get into faith schools. In any case, children are notoriously superstitious, always avoiding cracks in the pavement and so on. God is a useful backup to the head’s authority, and hell to the threat of missing the school outing.

But it cuts both ways. As Catholic schools showed, divine authority can also be a cover for physical and sexual abuse.

So where does the popularity of faith schools come from? I suspect most readers know the answer. The criteria for admission to many faith schools - religious commitment and attendance at worship - are proxies for supportive, often middle-class, parents who care about education, try to maintain a stable family life and keep their children under control.

I refuse to accept these characteristics derive from religious belief. The cause and effect are the other way round: the “good” family is more likely to believe, or pretend to believe, sometimes just to get places in a school that excludes “bad” families.

Indeed, if it weren’t for educational anxieties, religious faith would probably be in even steeper decline. It is a modern form of Pascal’s wager.

This 17th-century French philosopher argued that the rational course was to believe in God. If no God existed, nothing was lost. If He did exist, the rewards were stupendous and the penalties of unbelief terrible.

Likewise, today’s parents rationally calculate that they should at least have their children christened and send an occasional donation for the church roof, stepping up their commitment according to the state of local schools as the child approaches 11.

No wonder the churches are so keen to sponsor schools. It is by far the most effective form of promotion they have.

Peter Wilby is former editor of the New Statesman.