I adore much about the Church of England, profound atheist though I am. I raise funds for its cathedrals and parish churches, which I regard as absolutely intrinsic to the fabric of England. But because of what is happening with Islam, the sweet, confused C of E has, alas, to be disestablished. Britain must become a secular state.

In the late 20th and early 21st centuries, without even pondering the consequences, we have imported a significant community amounting to about one in 25 of the population who are at a different stage of religious development.

Founded in the 7th century, Islam is 600 years younger than Christianity. In Islamic time, it is still AD 1400. They haven’t had a Reformation, let alone an Enlightenment. And they treat their religion with the same kind of passion that we did when we burnt heretics.

The point is this. Because certain privileges were retained for the established Christian churches, there is the argument from equity. This says that because the right to have faith schools has been accorded to the Church of England, Judaism and Catholicism, therefore we must give it to Islam.

Similarly, in the House of Lords we have the extraordinary situation where religious leaders sit ex officio in the legislature. Only one other country entertains the practice — the Islamic Republic of Iran. Now it is being suggested that because bishops are represented in the Lords, therefore rabbis, Catholic archbishops and imams should also sit there. This, in the early 21st century, is grotesque.

What is the solution? Last weekend the Bishop of Rochester, Michael Nazir-Ali, warned that Britain may be too weak to resist Islamic fundamentalism “unless there is some reclaiming of the moral and spiritual tradition which created this country”. I think his history is simply wrong.

For it wasn’t a Christian tradition that created modern Britain but the reaction against it. This means that, rather than reprivileging Christianity, we should deny privilege to all religions. Instead we must regain the Enlightened confidence to put religion back in its box and assert once more that the separation of church and state is the foundation of modernity.

And nowhere is this lesson better taught than in our own history. From the time of Christ to the Middle Ages, Christianity made a clear distinction between the sacred and the secular. That position was completely reversed in England when Henry VIII made himself the supreme head of the church. He had started as the most passionate defender of the papal monarchy. But he wanted a son — and he wanted to marry Anne Boleyn more.

Eventually, Henry came to think he was actually Christ on Earth. And he and subsequent kings of England believed they had the absolute right, as God’s anointed, to change the religion of their people according to their own lights.

The Church of England now became a mere means to that end, by turning itself into a body that saw its prime function as preaching obedience to the monarch. The whole Christian doctrine of the separation of church and state was stood on its head.

In short, Henry introduced genuine totalitarianism for the first and last time in English history. The resources at the disposal of a 16th century king were, happily, not those of a 20th century dictator. But the aspiration was identical. Henry was the English Hitler-cum-Stalin, ordering the confiscation of the monasteries and instituting a reign of terror.

However, the fact that Henry assumed supreme religious power at the Reformation, when there was acute religious tension, meant that the monarch became a disputed figure in a way kings had not been in the Middle Ages.

The result was that the English, the first to experience this totalitarian fusion of church and state, were the first to get out of it. They were even the first to develop the doctrine of tyrannicide, which endorsed the deposition or murder of a monarch of the “wrong” religion.