In recent surveys, the religious "nones" -- as in, "none of the above" -- appear to lead in the faith marketplace. In fact, "none" could soon be the dominant label U.S. adults pick when asked to describe their religious identity.
But they may not be who you think they are. Today, "nones" include many more unbranded believers than atheists and an increasingly diverse racial and ethnic mix.
And, researchers say, this is already making nones' attitudes and opinions less predictably liberal on social issues.
A February survey by the Public Religion Research Institute of Americans found:
- 21 percent are "unaffiliated" (PRRI's umbrella term for a diverse group including atheists, seculars and people who still say they believe in God).
- 20 percent are Catholic.
- 19 percent are white evangelical.
"Nones are dancing on the razor's edge of leading," said Robert P. Jones, CEO of PRRI.
Meanwhile, the Pew Research Center's cumulative findings, based on 16,000 interviews in numerous 2013 surveys, found a slightly different split:
- 22 percent Catholic
- 20 percent nones (a mix of people who say they believe "nothing in particular," unaffiliated believers and unbelievers)
- 18 percent white evangelicals
However, both Jones and Greg Smith, director of U.S. religion surveys for Pew, caution this is really a statistical three-way tie for both research firms once the critical margin of error for each survey is considered.
Meanwhile, all the subcategories of Protestants -- white and black evangelicals, plus the mainline faithful -- still add up to a plurality (48 percent), though each has "distinctive social and political beliefs, attitudes and opinions," Smith said.
"The nones are clearly growing as a share of the population. It's a big, important, fundamental change in U.S. society, regardless of what's causing it and whatever else is happening," Smith said. "But does it necessarily mean that other religious groups are less healthy than they might have been? It may be that they are but there are other forces that are at play."
Those forces include immigration rates and religious switching. About half of Americans switch their religion, leave one or find one at least once in their lifetime.
Today's young adults are starting out more unaffiliated than any prior generation of 20-year-olds. So, even if some millennials do find a faith, Jones said, "they will still be the most unaffiliated generation in history."
Jones identified another force in shifting religious demography: "There are fewer white evangelicals among millennials (ages 18 to 33) because younger Americans today are more racially and ethnically diverse."
A PRRI survey found that second- and third-generation Hispanics are less likely to be Catholic than their parents or grandparents. Some move to evangelical, charismatic and politically conservative Protestant groups, but equal numbers are becoming simply unaffiliated, Jones said.
PRRI's 2012 American Values Survey broke the nones into three groups.
Atheists and agnostics (36 percent) are "overwhelmingly white," Jones said; only 12 percent are Hispanic or African-American. The second group, those who say they are "not religious" (39 percent), are 64 percent white and the remainder are racial or ethnic minorities.
However, there has been a surge in the third group, the "unattached believers," who believe in God but reject a religious brand (23 percent), Jones said. That group is also significantly more likely to include minorities: It's 56 percent white, 12 percent Hispanic, 23 percent African-American and 7 percent other.
"These are people who, by many traditional measures of belief in God and the Bible, look like people who are affiliated. But in the survey they say they are not attached to a formal religious tradition and do not even identify with a nondenominational Christian church," Jones said.
These "unattached believers" likely contributed to a surprising finding in the recent PRRI survey on attitudes toward lesbians and gays. While every religious group moved toward more acceptance of gay marriage in the last decade, 26 percent of the unaffiliated said "gay marriage goes against their religious beliefs," up from 18 percent in 2003.
Put another way, atheists, agnostics and secularists did not shift toward religion or opposition to gay marriage, but that third group now contains more "unattached believers" who bring with them their more traditional notions of sexuality, and they're now standing under the same umbrella.
No matter what you call them -- "nones," "unaffiliated" or "unattached" to "unbranded" -- they may be perhaps unreachable for the church, said Ed Stetzer, president of Nashville-based LifeWay Research.
"Most people in the past identified as Christians even if they didn't practice as Christians. Now that secularism is one of the biggest forces in our culture," Stetzer said, "they don't look to God, sacred texts or institutional religion as their prime frame of reference or authority for their values."
That alarms Bishop Emery Lindsay, presiding bishop of the small black Protestant denomination Church of Christ (Holiness) U.S.A.
After decades in the pulpit, first in Chicago and for five years as pastor at Christ Temple in Los Angeles, Lindsay said he sees more young African-Americans drawn away from church life than ever before.
"I meet people all the time who say 'I am spiritual, I believe in God, but I'm not connected or committed anywhere,' " Lindsay said.
Lindsay said "we don't have any optimum answers" on retaining young people but his church has brought in a young minister to "build some bridges" to youth.
Will they stay? The PRRI survey found that a significant number of young adults say a negative attitude toward LGBT people was one of the factors that prompted them to leave church.
Lindsay acknowledges that his denomination definitely opposes gay marriage. However, he said, the day has passed when pastors preached that "if you were in that lifestyle, you were definitely going to hell."
Instead of a "heavy message of condemnation," Lindsay said, "today's young people want us to affirm that these are people who struggle with a different sin, but we all have challenges with being a moral person."