THE notion that America spends its leisure time praying at evangelical megachurches is widespread; but the United States is a diverse country, and many of its people get their spiritual nourishment elsewhere. Some of them are in yoga studios, wearing prAna-branded stretch pants and chanting “Om”. Others are in spas and retreats, getting exotic massages; queuing at the Ayurvedic and Chinese-medicine counter at, say, Elephant Pharmacy in Berkeley; in psychotherapy sessions, to improve themselves or their marriages. If asked about their faith, many would answer that they are “spiritual, but not religious”. That may sound daft to both theists and...