The Church of England is the longest-running prevent strategy in history. If not from its inception, then certainly from the end of the English civil war, the big idea of the C of E was to prevent radicalisation – precisely the sort of radicalisation that led to religious people butchering each other throughout the 1630s and 40s. Its strategy was to discourage two things: big expansive politically minded theology – the sort of theology that has ambitions to change the world – and religious passion (or “enthusiasm” as it was dismissively described).

From the end of the 17th century, a new mood of religious inclusivity would dominate. Increasingly suspicious of theological dispute, the idea was to kill off God – or at least God-talk – with religion. People would all pray together, using the same form of words (the aptly described Book of Common Prayer), but be discouraged from discussing the ideological side of religion. Religion itself – going to church and so on – was reclaimable as a part of the much-needed project of national togetherness. It cemented all that one-nation, big-society stuff. But God had to be kept out of it as much as possible. Thus the formation of the English dinner party rules: no discussion of God, sex or politics. And under pressure not to “do God”, the wet non-committal English clergyman became a figure of fun – at best, a local amateur social worker, and at worst, a social climbing hypocrite. The Vicar of Dibley or Mr Collins. Thus God is defeated by religion. Indeed, one could even say that, for the English establishment, that is precisely the purpose of religion. They trap Him in boring services so that people won’t notice the revolution for which He is calling.

And then along comes Islam – and, thankfully, it disrupts this absurd game and refuses to play by the rules. Its practitioners want to talk about God, sex and politics rather than mortgages, school places and the latest Boden catalogue. And good for them. But David Cameron’s whole attack upon “non-violent extremism”, his upping the ante on the Prevent agenda, is an attempt to replay that clapped-out C of E strategy of stopping people talking about God in a way that might have social or political consequences. Cameron, of course, thinks of this sort of political God-talk as radical and extreme – which, by the standards of English dinner-party rules, it most certainly is. But had the Levellers of the 17th century not been radical or extreme, they would not have introduced England to democracy in the first place (something for which they were eventually rounded up and shot).

This week we learned that a three-year-old child was among a number of young people identified by the security services as being at risk of radicalisation. And it is increasingly becoming the responsibility of schools to watch people who display the worrying signs of radicalisation – signs like going to the prayer room too much, or wearing modest clothing. Do we really want to turn our educational establishments into part of the security apparatus? And do we really want to spy on universities for the presence of dangerous potentially world-changing radical ideas – like Plato or Marx or Jesus or Muhammad? This, apparently, is what Cameron calls “the struggle of our generation”. How bloody ridiculous.

Let me be clear. I condemn absolutely any theology that calls for or encourages violence. If people are doing that, arrest them. But “non-violent extremism” is, by definition, neither of those things. And attacking it is simply an attack on thinking big, thinking differently and arguing passionately. It comes from a now defunct C of E mindset (now defunct even within the C of E, thank God) that assumes it’s the job of religious people to be pastorally nice, softly spoken and uncontroversial. But that’s not Jesus. And like him, I believe in pulling the mighty from their thrones and lifting up the lowly. And I believe there is an authority greater than yours – one I would obey before I would obey the laws of this land. And if that makes me a dangerous extremist, Mr Cameron, then you probably ought to come over to south London and arrest me now.

@giles_fraser