For the last 1,700 years, to be English has meant to be Christian. This now seems to have changed for ever. “No religion” has now overtaken “Christian” as the majority position among white British people; and the younger they are, the more likely this is to be true.

Polling carried out by YouGov for Linda Woodhead of Lancaster University shows that if you’re under 40 and British, you are far more likely to report being “no religion” than either Christian or anything else. But if over 40, the proportions are reversed. What’s more, the children of no-religion parents are overwhelmingly likely to remain nonreligious themselves (95% do so), whereas the children of Christian parents will probably stop labelling themselves Christian – only 40% do.

These “nones”, as they are known in the jargon, are not all fervently atheist: only 40% are convinced that there is no God or “higher power”, and 5% of them are absolutely certain that He does exist. The figures neatly reverse the proportions among those who identify as religious, only 5% of whom are convinced atheists.

All this will make little sense if you think that religion is primarily a matter of belief. But Woodhead does not. She thinks that religions are made up of practice, ritual and self-understanding quite as much as theology. I should declare an interest here, since she and I are about to publish a book on the collapse of the Church of England, for which we discussed these very issues.

The point about British nones that distinguishes them from, say, American ones, is that they are almost entirely the people who would have been Anglicans in previous generations (for instance, they are overwhelmingly white) – and Anglicans generally have never been fervent believers. They are now being replaced by children and grandchildren who are unfervent nonbelievers.

Nonbelief takes rather different, often more enthusiastic forms in countries with different traditional ways of being Christian. This means that the growth of nones and the decline of Christianity in this country was not inevitable. In other places with different traditions, such as Scandinavia, identification with Christianity has declined much less. The proportion of Danes declaring no religion is still only 12%, even though Danes hardly ever go to church.

Why the Church of England lost its grip on the English imagination is a long and complex story. The obvious reason is that society has become less religious. In particular, it has become very much less obedient to traditional authorities.

Nones can’t stand to be preached at, and neither do they take any notice of religious leaders (with two and a half exceptions: they respect the Dalai Lama, Desmond Tutu and, to some extent, Pope Francis). But in this they are simply taking over the attitude of traditional religious believers in Britain, who also reject the official teachings of their churches.

The Roman Catholic rejection of the Vatican line on contraception and divorce is well known, but majorities of all the large Christian denominations in this country are in favour of euthanasia and liberal abortion laws. It’s just that the nones are more solidly in favour, and this divide is more marked when it comes to same-sex marriage.

Along with the statistician Bernard Silverman, Woodhead has developed a measure of liberalism on moral attitudes, defined as allowing people to make their own decisions, providing these do not harm others. Polling reveals that nationally there is a liberal moral majority of 83% as against 17% authoritarian. Even among Muslims and Baptists, there are majorities for this kind of live-and-let-live liberalism – certainly among Catholics (85%) and Anglicans (92%); but among nones it is absolute. All of them reject religions as a source of authority on personal morality.

But at the same time as people have been growing less religious, the Church of England has been growing more religious: more exclusive, more of a club for self-conscious believers, prouder of being out of step with the people it once served.

Only last week, Justin Welby was boasting to the other leaders of Anglican churches that the Church of England had secured exemptions from equalities legislation – and then complaining that he operated in an “anti-Christian culture”. What does he expect, when the church he leads systematically violates the moral intuitions of most of its own natural constituency?

Under those circumstances, it’s not really surprising that no religion has become the new religion, while “religion” has become something that other people do. The interesting question is whether Christianity in this country can ever recover, or whether some kind of organised humanism could actually replace it.