To help solve the conundrum, let's turn the question on its head. Rather than ask what causes people to believe, let's ask instead what causes militant atheists to hate religious belief so much. Why does it matter so much to them that people have religious faith? Why don't they just dismiss them as cranks and just leave it at that? Why does it matter so much, as the geneticist Richard Lewontin candidly admitted, that scientists will come up with crazy propositions in order to prevent "the divine foot in the door"? 

One clue, I think, lay in the slogan on the side of the bus hired by atheists back in 2009 to spread the non-believing word. That slogan read: "There's probably no God. Now stop worrying and enjoy your life." In other words, nasty religion puts constraints on your behaviour and makes you miserable. In order to enjoy life you just have to shake off religion and lose those constraints and then you will be happy. 

I think this fatuous slogan gets to the heart of why people have turned away from biblical religion — not because it is irrational but because it puts constraints on their behaviour. This is the source of the hatred — that biblical religion is seen as a restraint on the ability to behave exactly as you want. What such people don't realise is that true freedom only exists within constraints; and far from expanding freedom, unconstrained libertinism leads straight to abuses of power. As we can see from the ideological false faiths that are filling the vacuum.

Which leads me to my conclusion. The only way out of this, the slow throttling of freedom of thought by secular ideologies and the corresponding erosion of morality and order, is to return to the true faith of biblical religion. To which people say: this is impossible in a world governed by reason. But as I hope I have shown, it's not reason at all. People currently believe all kinds of rubbish. If they are prepared to believe a dozen impossible things before breakfast, there's surely no reason why they can't believe the one allegedly impossible thing for which there exist centuries of scholarly exegesis and an impressive measure of supporting evidence. All that's needed is for God to have some rather better PR — for rabbis and priests to start marketing their brands in more imaginative and attractive ways. Ways which don't duck the mystery at the heart of existence which the false faiths of ideology, no less than organised religion itself, are patently quite unable to explain.