Alexandra Burke, X Factor winner and Strictly Come Dancing contestant, described in last week's Radio Times how her Christian faith calmed her jitters before a show. Prayer found its place alongside lavender oil, Rescue Remedy, yoga and daily meditation as ways of 'get[ting] into the right frame of mind for the performance'.

'When times are hard or challenging, it's so important to find positivity and a way to see the best in your situation and in other people. For others that support doesn't come from the church but it's important that if you can't find it within yourself, you find it somewhere – it could be watching Strictly! Because we all need an escape – and where better than the world of sequins and glitterballs?'

It's not for us to judge Burke's faith. Let's be glad she has one. But her words play into a certain damaging stereotype of Christianity, namely that the real issue is about whether it works for you. Does it make you feel positive? Corresponding to reality, or describing things as they really are, seems unimportant, if not irrelevant. No wonder, then, that she concludes, in true talent show style, you be the judge!

The view of religion as a psychological crutch, as a flight from reality, is popular among secular people. But is it also held by people within the church?

Orthodox Christianity holds that moral statements, about what one ought to do or not to do, are universal and have truth value­. This means that they transcend cultures and personal preference. According to Christian teaching, reality is both moral and physical, and just as scientific statements are true if they describe something about the physical universe correctly, so can moral statements correctly or incorrectly describe the ways God intended for human behaviour. If I say, then, that it is right for people to worship God, I am proposing that it is true that God designed humans in a way that means they flourish best, as individuals and a community, when they set their hearts on him.

To say as much was uncontroversial in western culture until the 18th century Enlightenment. Societies believed in moral absolutes: one could no more decide that it was right to murder than make water flow up mountains. But since then, it has been thought that truth can only be discerned through our senses. Science is given the monopoly on truth and religion is at best something that offers emotional comfort. The first is allowed to articulate universal truths; the second, personal ones.

This is not without consequence. Alexandra Burke may have publicly spoken about her faith. But the faith she described was a privatised one, one that could have no place in the public square. For if it really is the case that what is true for you is true for you, and not necessarily for me, then it would be imperialistic to try to make you see things my way. Forget evangelism: rather than sharing the gospel, the most loving thing we could do is allow people to find whatever makes them happy, with no moral constraints. If there's no such thing as moral truth, then we could as easily recommend violence, for those who take pleasure therein, as a hot bath for those seeking a feel-good hit.

Crises of faith are also inevitable for those who use religion as a means of bolstering their ego. The feeling that prayers have gone unanswered, that God is distant, or that he does not really love us all litter the journey of faith – those walked by characters in the Bible as well as modern day believers. Feelings are an unreliable bedrock on which to establish your faith. If we determined God's character on the basis of what we felt that he was like, we would never arrive at a picture of a constant, steadfast, unfailingly loving God. He would be as fickle as we are.

Jesus called us to love and forgive those who we don't feel deserve it, to resist feelings of temptation, to count ourselves blessed when we undergo trials of all kinds, and to follow him even to the point of persecution and death. Christianity does not by any means deny the richness of human emotional experience. Feelings are not to be denied. But they do not get the final word on establishing truth. 

If Burke is not alone in how she understands faith, then it is clear that apologetics needs a greater role in our churches. Rather than reserving talks on arguments for God's existence, the historical evidence for Jesus, the historicity of the Bible and so forth for evangelistic talks, there should be a place for them in Sunday services as well. Because seemingly it is not just people outside the church who need convincing of the truth of Christianity: it is those inside as well.