Study: 25% of us have left childhood religions

More than a quarter of American adults have left the faith in which they were raised, switching to another religion or no religion at all, according to a national survey of religious affiliation.

In addition, adults who claim no ties to any religious institution have grown into the fourth largest category of religious affiliation, a trend led by California and states in the West, according to a report by the Pew Forum on Religion and Public Life.

Researchers said the large number of immigrants who have come to California from Central America and Asia have had an effect on the question of religious affiliation in the state as well as the makeup of particular denominations, particularly Catholics. While 10 percent of U.S. adults have left the Catholic Church, an influx of Catholic immigrants has kept the church's population stable.

Because the numbers of the unaffiliated have grown, Protestants are on the verge of becoming a minority in the United States. Only 51 percent of American adults describe themselves as Protestant.

In addition to the 28 percent of Americans who have left their childhood faith entirely, 16 percent have switched from the Christian denomination of their childhood to another Christian denomination.

The fluidity of affiliation in the United States underscores the competitiveness of the religious market, in which groups are vying for members, said Luis Lugo, director of the Pew Forum. "If you're going to rest on your laurels, you're history."

The survey of more than 35,000 adults was distinctive in the number of respondents as well as the number of questions posed. It found that 78 percent of the 220 million adults in the United States are still Christian.

Among Protestants, evangelicals are the largest single group, representing 26.3 percent of the nation's adult population. Mainline Protestant denominations - including Methodists, Presbyterians and Episcopalians - continue to see their numbers shrink, currently representing just 18.1 percent of the overall population. Historically black churches, which are increasingly taking on members of other ethnicities, represent 6.9 percent of the overall population.

Catholics are the second largest group of Christians, representing roughly 24 percent of the population - a relatively constant figure for the past 35 years.

But the constancy of that figure obscures the dramatic and unique way in which immigration patterns are reshaping America's religious identity, the survey found. Unlike in Europe, the majority of immigrants to the United States are Christian. And those immigrants are heavily Catholic, particularly those from Mexico.

Among immigrant adults, Catholics amount to 46 percent, while 24 percent are Protestants. But among U.S.-born adults, Protestants outnumber Catholics 55 to 21 percent.

The departures from the church mean that "roughly 10 percent of all Americans are former Catholics," the study found. While 31 percent of American adults were raised Catholic, only about 24 percent describe themselves as Catholic today.

These shifts are seen throughout the Bay Area, said George Wesolek, director of the Office of Public Police and Social Concerns within the Archdiocese of San Francisco.

St. Peter Church in the Mission District draws about 25,000 people every weekend, Wesolek said. The Catholic churches in East Palo Alto, the Bay Area's most heavily Latino city, hold most of their services in Spanish, he said.

The responsibilities of the parishes, the social mission of the church and the needs of the congregants are changing as a result.

"The Latino and immigrant base of the church is now making up the core, especially in California," said Wesolek, noting that Filipinos are a large portion of the archdiocese. "That has implications in almost every way." Priests must be multilingual, for example, and be able to meet the needs of different cultures.

The Western states have long been a destination for immigrants as well as the native-born, said John Green, a senior fellow at the Pew Forum and a principal author of the study. That mobility and lack of deep roots also play a role in the region's higher rate of the religiously unaffiliated, Green said, referencing other studies.

"The West was settled relatively late," he said. "It didn't have the tradition of established religious institutions that you have in the East or the South. They didn't have that history to draw upon."

That is compounded by immigration, particularly from Asia, which has brought other religious traditions, and that makes Western states like California distinct, he said.

"The West has always been quite diverse in religious terms and is especially diverse these days," he said. "And that level of diversity has created a group of people who aren't as interested in organized religion. They have other options."

Roughly 16.1 percent of the U.S. population describes themselves as not affiliated with any religious organization or body, a category that includes those who believe in God. In California, the unaffiliated account for 21 percent. Researchers said the numbers of atheists and agnostics - roughly 1.6 and 2.4 percent of the U.S. adult population - have remained consistent over time.

Those who are raised unaffiliated change their beliefs, too: Roughly half of those who were raised without a religious tradition now claim one as adults, according to the survey.

Green said the impact of the unaffiliated has yet to be seen. But it needs to be watched.

"The large size of this unaffiliated group could have a profound affect on the character of American religion," he said.