So, a Muslim and an atheist walk into a church. "Who's taking the service today?" asks the Muslim. "I think it's my turn," says the atheist. "You did it last week."
If that happened in a church, we'd probably be outraged – not because we have anything against either Muslims or atheists, but because it wouldn't be appropriate for someone of a different faith, or of no faith at all, to conduct a service of Christian worship.
But all over the country, every day, that's exactly what's happening. The 1988 Education Reform Act requires an act of worship in schools which is "wholly or mainly of a broadly Christian character". There are opt-outs, in that worship can reflect the "family backgrounds" of the pupils and not every act of worship has to be Christian; but legally, you have to worship. At its worst, this means that teachers with no faith of their own might have to conduct a service in the name of a God in whom they don't believe, with a congregation of similar non-believers who are all being encouraged to sing lustily, "O Jesus, I have promised".
It's against this background that the Bishop of Oxford, the Rt Rev John Pritchard, has got himself into a spot of media bother. He's the head of education for the Church of England, and he says that compulsory participation in religious worship is a relic of the 1940s (it was part of the groundbreaking 1944 Education Act) and should be dropped in favour of a time of "spiritual reflection".
His comments came after the National Governors' Association, which represents more than 300,000 school governors in England, also called for the requirement to be scrapped for all non-religious schools.
Say that religious assemblies are scrapped. Is this just another nail in the coffin of Christian Britain? Some would certainly say so. Adults who grew up singing "All things bright and beautiful" and "Morning has broken", and who remember the Lord's Prayer in the traditional version might regret the fact that succeeding generations won't. There's a loss of continuity; another few words of our shared vocabulary have dropped into history's dustbin.
Society, too, will become marginally less "Christian". There'll be even less knowledge of the foundational Gospel stories than there is now, and – so the argument runs – it'll be even harder to convert people.
The really apocalyptic scenario, of course, is that we descend into a sort of pagan barbarism again. Without their daily dose of corrective morality, children will become feral – or even worse, according to a spokesman from Christian Concern: not really British. (Andrew Marsh referred in an interview on Voice of Russia to calls from politicians to beef up teaching on British values after the Birmingham schools scandal and said: "It's striking we have that on the one hand and then have calls to remove the act of common worship that helps young people understand what has given rise to British values and what undergirds them.")
Now, in practice, the scenario on the ground doesn't usually justify extreme rhetoric from either side. Certainly, Church schools can produce daily worship with integrity, as long as they remember that a good number of those they are asking to sing the aforesaid "O Jesus, I have promised" will have done no such thing. In fact, even in non-Church schools, assemblies are often sensitive and thoughtful – and many have taken the pragmatic decision to ignore the letter of the law and deal with the fallout if there is any.
Nevertheless, there are some points of principle at stake.
* Are we really happy that non-Christians conduct Christian worship, even if it's only "wholly or mainly of a broadly Christian character"?
* Do we fundamentally believe that it's up to the state to mandate the formation of children as Christians?
* Do we believe that schools are about religion, or about education?
* Is our resistance to dropping religious assemblies really about fear of losing Christianity's historic advantage in the spirituality stakes?
* If so, shouldn't we be a bit ashamed of ourselves?
Let's be clear: I'm all for religious education. This Government has been roundly criticised by the Religious Education Council for cutting support to RE teachers and MPs have come out in its defence. But the place for religion in schools is the classroom, not the assembly hall.
I still recall an old head-teacher who told me that religious assemblies should be dropped, long before the idea gained the sort of traction it has now. "It inoculates children against religion for life," he said.
So instead of Churches fighting tooth and nail to retain a privilege they don't need and shouldn't want, I'd love to see them – just for a change – in the vanguard of calls for its abolition. I'm backing the bishop.
Rev Mark Woods is a freelance writer and Baptist minister.