I have spoken at dozens of weddings, but never at a civil ceremony. Being a vicar, it was something of a challenge. "The law will not permit the use of any wording, readings or music which may have religious connotations at a civil marriage," is how the Weddings in Westminster brochure explained the limitations. That seemed a mighty sweeping prohibition - I can get "religious connotations" from pretty much anything. Under these circumstances, what could I say that would be of any use to the happy couple? Indeed, what could I say at all?

I phoned up the register office people to explain my plight. Things got worse. They weren't sure if I could say my few words wearing a clerical collar. And it was suggested that I might have to submit my script in advance for clearance. I had heard about this bonkers state of affairs before - of a couple who were banned from having a CD of Robbie Williams singing Angels at their wedding because it was too religious - but this was my first run-in with the secular culture police. This summer, all over the country, wedding couples will be told that they can't have a Shakespeare sonnet or Elizabeth Browning's How Do I Love Thee because it has some whiff of the divine about it.

In the end I made a gag about the restrictions and spoke, tongue in cheek, about the chemistry of love: testosterone, oestrogen, oxytocin, phenethylamine. I made no use of the banned G word. Instead, I drew chemical symbols on large boards that I then presented to my atheist mates Mick and Nicky with the no-doubt hopeless explanations of what these chemicals brought to a relationship.

But why have we prohibited from civil weddings some of the most moving and thoughtful reflections on the ways of the human heart? Why are we allowed only to paint from the limited palate of strict empiricism when this, above all days, is when we ought to be making fullest use of the language of love? I left the wedding grumbling to myself about secular control-freakery, all pumped up to write something fierce about the way the secular has turned into a campaign for the systematic eradication of all religion from the public sphere.

But I had got this one all wrong. There is no secular plot - indeed, the truth is almost the reverse. In 2005, the government published a consultation document on proposed changes to the current guidelines. "The religious organisations who responded were unanimous that no readings from religious texts should be allowed, even if they did not directly refer to the deity." The Catholic bishops were totally against allowing religious texts to be used. "Through secular use their particular religious meaningfulness can be diminished," they argued.

So, the reason you can't mention God in a civil ceremony is because the churches won't allow it. If there is any control-freakery here, it is from church authorities acting as though the Bible were their property and that they alone have the wisdom and responsibility for interpreting God. Members of the public can't be trusted to understand the Bible on their own or to use it respectfully. Just think - horror of horrors - what if a gay couple were to want a Bible reading at their civil partnership? Here, then, is the real scandal behind the prohibition of religious readings in civil ceremonies. It's all about monopolising the divine.

In 1401, Henry IV passed a law that forbade ordinary people owning a Bible. Those caught were burnt at the stake. The Reformation did away with this - the Bible was to be available for all and did not require a priest in order to show people how it must be understood. Which is why, at a civil wedding, the couple ought to be able to have whatever readings and music they choose. There is no secular transgression here, for it grants religion no special privileges. It simply recognises that the Bible is literature too - and owned by no one.

· Giles Fraser is the vicar of Putney

giles.fraser@btinternet.com