In one striking passage, Mr. Stearns quotes the prophet Ezekiel as saying that the great sin of the people of Sodom wasn’t so much that they were promiscuous or gay as that they were “arrogant, overfed and unconcerned; they did not help the poor and needy.” (Ezekiel 16:49.)

Hmm. Imagine if sodomy laws could be used to punish the stingy, unconcerned rich!

The American view of evangelicals is still shaped by preening television blowhards and hypocrites who seem obsessed with gays and fetuses. One study cited in the book found that even among churchgoers ages 16 to 29, the descriptions most associated with Christianity were “antihomosexual,” “judgmental,” “too involved in politics,” and “hypocritical.”

Some conservative Christians reinforced the worst view of themselves by inspiring Ugandan homophobes who backed a bill that would punish gays with life imprisonment or execution. Ditto for the Vatican, whose hostility to condoms contributes to the AIDS epidemic. But there’s more to the picture: I’ve also seen many Catholic nuns and priests heroically caring for AIDS patients  even quietly handing out condoms.

One of the most inspiring figures I’ve met while covering Congo’s brutal civil war is a determined Polish nun in the terrifying hinterland, feeding orphans, standing up to drunken soldiers and comforting survivors  all in a war zone. I came back and decided: I want to grow up and become a Polish nun.

Some Americans assume that religious groups offer aid to entice converts. That’s incorrect. Today, groups like World Vision ban the use of aid to lure anyone into a religious conversation.

Some liberals are pushing to end the longtime practice (it’s a myth that this started with President George W. Bush) of channeling American aid through faith-based organizations. That change would be a catastrophe. In Haiti, more than half of food distributions go through religious groups like World Vision that have indispensable networks on the ground. We mustn’t make Haitians the casualties in our cultural wars.

A root problem is a liberal snobbishness toward faith-based organizations. Those doing the sneering typically give away far less money than evangelicals. They’re also less likely to spend vacations volunteering at, say, a school or a clinic in Rwanda.

If secular liberals can give up some of their snootiness, and if evangelicals can retire some of their sanctimony, then we all might succeed together in making greater progress against common enemies of humanity, like illiteracy, human trafficking and maternal mortality.