Americans are more willing than ever to leave the faith they grew up in to embrace another -- or no faith at all, according to a survey released Monday that reveals the nation's religious culture as a vibrant and oft-changing landscape.

More than a fourth of adult Americans have a different religious affiliation than the one they grew up in, the survey by the Pew Forum on Religion and Public Life found. That figure reflects a lumping together of all the Protestant faiths; when differences are drawn among Protestant denominations, the number skyrockets to 44 percent.

Those numbers are indicative of what's going on in Minnesota, too, said the Rev. John A. Mayer, executive director of City Vision, a Minneapolis organization that tracks religious demographics. "We're not just talking about switching churches," he said. "These are people who are switching religions."

"People will be surprised by the amount of movement by Americans from one religious group to another," said Luis Lugo, director of the Pew Forum, which interviewed 35,000 adults for the survey.

The trend was reflected in the number of people who don't profess a loyalty to any particular religion. Sixteen percent of adults fall into this category. When the responses are limited to people under 30, the number jumps to 25 percent.

The Pew report said that the Roman Catholic Church is taking the biggest hit. One-third of respondents who said they were raised Catholic no longer attend that church. But Mayer said that's one area in which Minnesota is bucking the national trend. "Catholic church membership is holding steady and even increasing here," he said.

The Rev. Kevin McDonough, vicar general of the Archdiocese of St. Paul and Minneapolis, said there are two likely reasons for that.

"In Minnesota, there is a sense that this is my parish ...and that this social organization is our ... social organization," he said.

"Plus, we have friendly competition with the Lutherans," he said. "We're the two biggest religions in Minnesota. Our relationship is friendly in that we cooperate. But it's also competitive in that there are a lot of marriages where one person is Catholic and the other Lutheran, and there's a feeling that if I don't get it done in my church, a couple is just going to go down the street to Pastor Olson's church. And vice-versa."

Finding their spiritual home

John and Carol Humphrey of St. Louis Park are a case study in the nebulous nature of religious affiliation. A product of a Catholic-Lutheran marriage, she was raised Lutheran until she was 6, when the family became Catholic. He was raised a Congregationalist.

When they got married, he tried to convert, "but I was a miserable failure as a Catholic," he said. "Some people like ritual, and I appreciate certain rituals more as I get older. But I felt that it got in the way of my prayer, and I couldn't ever get around that."

So they switched to Plymouth Congregational Church in Minneapolis.

"I'm glad that I had a Catholic upbringing because of everything I learned," Carol Humphrey said. "There were times when I thought I might miss it, but I've never regretted going to Plymouth. I love the social activism and the emphasis on the arts."

Other survey findings

• Protestants are still in the majority, but the difference is down to 51 percent. As recently as 25 years ago, the number was 66 percent. The cause is not so much Protestants deserting but a factor of immigration. Most immigrants are not Protestant.

• We're still a Christian nation, with 78 percent of respondents identifying themselves as such.

• More than a third of married couples mix faiths. Of married respondents, 37 percent are married to someone who practices another religion. (Protestant denominations were considered separately.)

• While Islam and Hinduism are practiced mainly by immigrants, 75 percent of the people who consider themselves Buddhist are natives who converted.

Jeff Strickler • 612-673-7392