The Marketplace of Faith

Americans love to shop, even for religion. More than 40% of U.S. adults have changed their faith since childhood, many opting for no faith at all. That's the key finding of a major study by the Pew Forum on Religion and Public Life, which surveyed 35,000 people in five languages to create the most detailed portrait yet of the country's religious landscape.

The study found that the fastest-growing religious group is people without any religious affiliation. But that doesn't mean the U.S. is experiencing a secular surge. Most in this group aren't atheists; they just describe their religion as "nothing in particular."

Catholicism has experienced the biggest exodus of members, though that has been offset by a huge influx of Catholic immigrants, mostly Latinos. Immigrants are fueling growth in other faiths too. Two-thirds of U.S. Muslims are foreign-born.

Protestants remain a bare and strikingly diverse majority; the study found widespread movement among 100 variations of Protestantism. For America's faithful, it's a buyer's market.