Religion has become one of the most contentious issues in the UK, exerting as it does an influence disproportionate to its waning popularity. I mean, we still have bishops sitting in the House of Lords, unelected clergy in our legislature, which puts us on a par with that other great pillar of democracy, Iran. It makes David Cameron’s happy-clappy outbursts last week all the more bizarre, writes David Stirling in The Evening Times