At the Lambeth conference, which meets once a decade, bishops from the 38 provinces of the worldwide Anglican communion gather to think, pray and talk about sex. No binding votes are cast, but Lambeth has been a venue for airing Church preoccupations since it was first convoked in 1867. For decades, women, gays, abortion, polygamy and venereal disease have divided the attendees. At this year’s conference, which starts on July 20, the bishops are expected to clash over the ordination of Gene Robinson, a non-celibate gay man, as bishop of New Hampshire in 2003. In recent days, the Church of England, at its general synod, approved ordaining women bishops, souring relations with the Vatican. And the London press revealed that one C of E priest had celebrated an unofficial gay marriage ceremony for two others.

The only thing preventing a walkout by conservative bishops is that so few of them are attending the conference to start with. A thousand conservatives, mostly Africans, including 300 bishops, travelled to Jerusalem last month for an alternative meeting, the first Global Anglican Future Conference. Bishops from Nigeria, Uganda and Kenya plan to boycott Lambeth. Many are on the verge of a “breaking of communion” with the mainstream US Church over its policies on gays. Why, in general, is sex such a pressing issue for religion just now? Why, in particular, does homosexuality among US Episcopal priests threaten to tear up a world religion in a way that, say, the past decade’s revelations of homosexuality among US Catholic priests did not?