The Church of England is woefully unprepared for the ideological winter that is to come. For too long we have been made content by feeding off the crumbs left out for us by the establishment. We have become its pet. And it has made us lazy. Housetrained. Safe. The Bible uses a different image: if salt has lost its saltiness, what use is it?

This week, the National Centre for Social Research published data showing that just over half the UK population describe themselves as having no religion. And only 15% see themselves as being a part of the national church, the Church of England. Which is why the disestablishment of the church is now both necessary and ultimately unavoidable.

Make no mistake, disentangling the church from the state will make Brexit seem like child’s play. It is easy enough to unseat a few bishops from the House of Lords. But it would be three-dimension jelly chess to redesign the relationship between the monarch and the state without the Christian adhesive of the coronation. Good luck with rethinking the monarchy after that one. And while you are about it, don’t forget those two most terrifying words in the English language: President Blair.

I always used to think that no political party would be prepared to give disestablishment the time and effort that it would require. But Prime Minister Corbyn might just be the man to do it. And far from being a fusty move for constitutional committees, disestablishment could be framed as an attempt to rationally redesign a Britain fit for a global role beyond the EU. After all, who needs Christian morality in the age of human rights?

Don’t get me wrong. I do not warm to the state of affairs that I have just described. Indeed, I feel profoundly alienated from such a country. It is just that I think something like this is unavoidable and that the established church has to get ahead of the situation by transforming itself, rather than play a continuous rearguard action against the inevitable.

But there is opportunity here for the church, as well as loss. What we give up is our traditional role as courtiers. Good, I say. The banners of the New Model Army would proudly proclaim that there is no king but Jesus. And to say that Jesus is the supreme authority is to say that no one else can be – not the Romans, not the pope, not the House of Stuart or the House of Windsor. The Church of England was specifically designed to soften that thought, to make it less dangerous. Christians were to be housetrained. We were to give up all our revolutionary talk of bringing God’s kingdom to earth and settle instead for a warm vicarage and being nice to our parishioners. That settlement is about to be ripped up.

I do not believe that disestablishment will revive the numerical fortunes of the church. Looking at our disestablished cousins, I think it may well mean we will decline at an even faster rate – at least in the short to medium term (and that means centuries in church terms). But please, my fellow Anglicans, we need to go before we are no longer welcome. And go in the knowledge that, as people of the resurrection, we do not fear death – either personally or institutionally.

The church of tomorrow will be smaller and saltier. It will be less bothered about dressing up in peculiar clothes, and less interested in playing nicely with those in power. There is much about our tradition that we must try to retain, not least our commitment to localism and our advocacy for the poor and marginalised. The church has always worked best when it shares in the apparent insignificance of our Lord’s humble circumstances. This is where we pan for glory.

As far as the wider culture is concerned, for now at least, we are to become what Stanley Hauerwas has called “resident aliens”, a social alternative to the dominant culture of secular and capitalist individualism, in the world but not of the world. Christians are now living through a period of rapid social change. We are called to carry a torch through difficult times. And we must equip ourselves with different skills for the challenge.