‘I’m not religious – I’m spiritual,’ is an increasingly common sentiment on both sides of the Atlantic. But what does it mean? Is self-styled ‘spirituality’ simply a different form of religion, or does it represent a fundamental departure, even a threat to traditional religion?

Around 80 per cent of Americans identify with a religious denomination – overwhelmingly Christian – while 40 per cent say they attend weekly services and 58 per cent pray at least once a week. This high level of religious observance, symbolised by America’s bustling ‘megachurches’, is unique in the developed world. And from raging debates about creationism to political candidates proclaiming their religious convictions, religion seems to be at the centre of American life. Significantly, though, those under 30 are less religious than ever before. Moreover, professor of religion Stephen Prothero suggests there is enormous ‘religious illiteracy’ in the US, particularly among young people. So does the persistence of high-profile religiosity mask a more profound decline in religious faith? And how does the turn to the spiritual fit into the picture? In Britain, numbers attending church have been decreasing continually in the postwar period, but there too there still seems to be a desire to have some kind of ‘spiritual’ outlook – often involving a pick-and-mix approach to eastern religions as well as Christianity itself.

Are authors like Sam Harris and the late Christopher Hitchens right to argue religious Americans have been duped somehow into adopting irrational beliefs? Or is it the New Atheists who are to be pitied for their lack of belief in anything beyond themselves? Some argue there is a psychological, biological and emotional drive to feel some kind of resonance with something like the divine. Some have even suggested environmentalism is a new form of secular religion, and psychotherapy is an attempt to handle sin and confession in a scientific way. Others see both the decline of religious faith and its apparent revival (in the form of Islam as well as some types of Christianity) as a reflection of broader ideological developments in recent history, in particular a loss of faith in human progress. So is the rise of ‘spiritual’ sentiment just another expression of our religious nature as human beings, or is it something new? And is it to be welcomed as life-affirming, or challenged as a new form of superstition?