A panoramic snapshot of American religious life in 2008 reveals an extraordinary dynamism that is reshaping the country’s major traditions in historic ways.

Almost half of all Americans have moved to a different religious denomination from that in which they were raised. The fluidity is combining with immigration to spur dramatic changes in the religious landscape.

“Religious fluidity is part of a larger picture of fluidity in American life generally,” observes Wade Clark Roof, author of Spiritual Marketplace and professor at University of California-Santa Barbara. “You can read this as ‘It’s what America is about’—we choose.”

According to a landmark Pew Forum on Religion & Public Life survey, Protestantism, which has shaped American identity for generations, may soon become a minority faith, as 51 percent call themselves Protestants today, while only 43 percent of those ages 18 to 29 say the same.

Currently, “Within our society, Protestants basically outnumber Catholics two to one,” says Luis Lugo, Pew Forum director. “Among immigrants, Catholics outnumber Protestants by more than two to one.”

While Christianity retains the allegiance of 78 percent of Americans, nondenominational churches are growing and now attract about 5 percent of adults. Other world faiths—Judaism, Islam, Buddhism and Hinduism—also collectively account for 5 percent.

Today, 16.1 percent of adults say they are unaffiliated; one quarter of those 18 to 29 are in this group. Researchers found that 1.6 percent of adults consider themselves atheists, and 2.4 percent are agnostics, who consider God unknowable. The remaining 12 percent split evenly between the secular and the religious, who may practice faith on their own. Although “unaffiliated” surfaced as the fastest-growing category, the survey shows that about half end up returning to a faith connection.

Pew’s U.S. Religious Landscape Survey of 35,000 Americans reveals that nine in 10 Americans believe in the existence of God or a Universal Spirit. More than half attend services regularly and pray daily. Among the unaffiliated population, four in 10 say religion is at least somewhat important in their lives, seven in 10 say they believe in God, and more than a quarter say they attend religious services at least a few times a year.

Seventy percent of Americans affiliated with a religious tradition do not believe that their faith is the only way to eternal life.

For details see Religions.PewForum.org/reports.