David Cameron’s comments about the importance of Christianity in Britain have dominated the headlines over the past week. Whether or not he is pleased with the coverage is another matter.

There has been a marked divide in reaction to his article in the Church Times of 16 April: while traditionalists such as the Telegraph's Charles Moore have leapt to his defence, others have pointed out how the prime minister has inadvertently managed to highlight the benefits of secularism.

On Easter Sunday a collection of 55 figures – some authors, some academics, not all of them atheists – wrote to The Telegraph to point out that Cameron’s politicisation of faith is unwelcome in a country that is chiefly secular and less religious by the day. (New Humanist's editor Daniel Trilling made the same argument in a piece on 17 April.)

On the other side of the argument, three articles – one by Stephen Glover for the Daily Mail, and two for The Telegraph by Timothy Stanley and Charles Moore – label those who would prefer to see religion left out of politics “militant atheists”, who allegedly pose a grave threat to the survival of the country. These writers echo the view recently expressed by Cameron's communities secretary Eric Pickles that Britain certainly is a Christian country and that anybody who disagrees needs to get over it.

Yet even while fervently defending Cameron’s assertion that Britain is a Christian nation, Moore, for example, reluctantly admits that people no longer treat it as such, nor like to think of it as one. In admitting this, he rather undermines his own argument:

[T]he angry atheists are surely speaking truth when they say that “we are a largely non-religious society”. If there is a battle in Britain nowadays between something explicitly Christian and something secular, the latter usually wins. Look at Sunday shopping, mass abortion, the growing desire to kill old people (sorry, let them “die with dignity”), divorce, surrogate motherhood and so on. For better or worse, religious objections couched as such tend to be disliked and rejected (unless they are made by Muslims, in which case people get scared of causing offence).

By this logic, we would still be "a Christian country" regardless of how few people follow the religion.

But the debate over whether Britain is or isn't a "Christian country" is perhaps less important than asking whether it should be one. The National Secular Society argues that the conversation ought to be about whether or not Britain would be “a fairer and safer place” with a secular constitution:

Let's be clear at once that we have no problem with Mr Cameron wearing his personal religion on his sleeve. Just so long as he is not intending to use his position as leader of the nation to give Christianity a special voice in policy-making that will affect us all, religious and non-religious, Christian and non-Christian, then that's fine. But from his recent statements it is difficult to avoid the conclusion that he does intend to privilege Christianity.

That Britain is a country shaped by its Christian heritage is not in doubt. What matters is that we confront the situation today honestly. It is fruitless to deny that Christianity has lost its dominance; as surveys repeatedly show, more and more people are walking away from the religion. If we are to leave faith out of politics – and polls often suggest that we want it so – it is crucial to recognise the shrinking role that religion plays in many people’s day-to-day lives.