America was famously founded by companies and churches. The woes of American capitalism are well known: Wall Street is a synonym for excess and greed around the world, and Detroit is tottering on the edge of bankruptcy. But just as its temples to Mammon are under fire, so suddenly are its churches to God.

With Easter week upon us, Newsweek's April 13 cover proclaims "The Decline and Fall of Christian America." The new American Religious Identification Survey (ARIS) shows that the proportion of Americans who claim to have no...