PEOPLE are surprised when they discover that I am a Christian, because I don't look Christian. I am an academic with the typical tribal features: socially liberal, politically leftist, feminist, pro-choice, and gay-friendly. When they find out that I am a Christian, they assume that I hold strange views about issues including the post-mortem fate of non-Christians and the origin of species.

Americans in the aggregate are very religious, but American religion is unevenly distributed across regions, classes, and ethnic groups. In the South, when you meet someone for the first time, a polite opener, after details of name and family ties are established, is: "Where do you go to church?" Yet in urban-coastal areas, among upper-middle-class "knowledge workers", God is not done.

Churchgoing is rare among educated professionals, and has become unmentionable. If you let slip that you have attended a church event, however social and secular, people worry that you are preparing to proselytise. Employers worry that churchgoers will offend coworkers and clients. A recent study by sociologists at the University of Connecticut reported that job applicants who mentioned any form of religious affiliation on their résumés were 26 per cent less likely to be contacted by employers than those who did not.

It is not hard to see why. Since the rise of the Religious Right, conservative Evangelicals have become highly visible and noisy. Their campaigns to promote conservative social agendas are always in the news, and politicians on the Right loudly proclaim their support. Employers are wary of applicants who, they worry, may have axes to grind, who might annoy colleagues by proselytising, or offend them with their views on hot-button issues.

So mainline Christians keep their heads down. There is also the Great Unmentionable: in the United States, Christianity is déclassé. Admit to it in polite society, and you will be suspected of being a homophobic, climate-change-denying, junk-food-eating member of the great unwashed.

Christians are not, as conservative Evangelicals claim, an oppressed minority whose religious freedom is under threat, or, as secularists complain, an oppressive majority. We are, increasingly, a stigmatised group, like smokers and the obese - and like our forebears, before Constantine made Christianity respectable. We began as a peculiarity in a morass of syncretic Hellenistic spiritualities, oriental cults, and self-help programmes, and were despised as superstitious by a secular elite. And now, in the US, in our beginning is our end.