Are you married?

Yes, a wife, house, children; the whole darn catastrophe!
[Zorba The Greek]

Question: "Do you have any religion?"
Old gentleman patient: "No. I'm Church of England."

The problem is that the gentleman in question was the Archbishop of Canterbury!

That's a very old joke.

Benjamin, he really said that and he was not joking, just making an off-hand remark.

It's an old cliche. A while back atheism was unfashionable, so when asked one's religion it was normal to reply CofE to get them off your back without embarassing questions about when you was last in church or confession. (Or why you were eating that bacon sandwich, or whatever.) Everyone knew what it meant without having to do anything so unBritish as to actually make people say it, and it was, after all, regarded as the official state religion. I suspect the fact that the man was elderly is the most significant datum.

Nowadays, wags prefer Church of the FSM, or Jedi Knight; now that challenging the surveyor's assumptions is considered more positively. It's all about putting people into boxes with labels...