The rise in the number of Americans unaffiliated with any religion is nothing new — and for some denominations, it might even be a good thing, religion scholars say.
The Pew Research Center for Religion & Public Life reported in a massive study this week that 22.8 percent of Americans identified with no organized religion, a dramatic rise from 16.1 percent in 2007, the last time the nonprofit research group took such a sweeping look at religion in America.
"The American religious landscape increasingly resembles a collage with blurring lines and overlapping boundaries," said John Green, a professor of political science at the University of Akron and a leading scholar of the role of religion in American society.
"It shows a trend moving from highly traditional to consistently secular perspectives," Green said.
While attention-getting for its speed, the underlying trend has been recorded by many studies over many years.
The General Social Survey of the University of Chicago's National Opinion Research Center, for example, has tracked drops in religious affiliation and church attendance for more than 40 years. Last year, 21 percent of adults reported no religious affiliation, compared to 8 percent in 1990 and 5 percent in 1972
And the American Religious Identification Surveys, a project of Trinity College in Hartford, Connecticut, reported that the proportion of American adults identifying themselves as non-believers fell from 86 percent in 1990 to 76 percent in 2008, the last year it conducted a full sampling.
But it's easy to overlook an important point — the U.S. remains overwhelmingly Christian, with 7 of 10 Americans identifying with a Christian faith, according to the unusually broad Pew study, which surveyed 35,071 Americans from June through September of last year, reporting an margin of sampling error of just plus or minus 0.6 percentage points.
While "the bad news is already dominating media reports ... we are still a Christian nation," said Bill Donohue, the outspoken president of the hard-line Catholic League for Religious and Civil Rights.
Still, Alan Cooperman, Pew's director of religious research, said it's indisputable that the number of self-identified Christians is declining in the U.S. — part of "a broader withdrawal from [organized] institutions" of all types.
The 200-page Pew survey didn't dive into why that's happening — that could come later this year, when the organization is expected to release a second report on specific beliefs and attitudes of the survey sample.
A breakdown of the raw numbers yields clear demographic trends, however: Younger people are more likely to be unaffiliated than older people, and single people are far less likely to identify with a religion than married people. Both of those comparisons roughly track with other polling indicating that self-identified liberal voters are younger and less likely to be married.
Most striking is the age cohort. Only 56 percent of so-called Millennials (roughly describing the generation born between 1980 and 2000) identify with a religion, Pew found. Cooperman said they may be turned off by the visibility of conservative spokesmen in American politics.
The second big driver in non-affiliation since 2007 is religious "switching" — the changing (or dropping) of the religion people were raised in when they become adults, a phenomenon that's even more common when people marry.
"By a wide margin, religious 'nones' have experienced larger gains through religious switching than any other group," Pew found. "Nearly one-in-five U.S. adults (18%) were raised in a religious faith and now identify with no religion."
The phenomenon can go in the other direction, and Pew found that 4.3 percent of adults went from non-belief to belief. Still, that means that for everyone who's joined a religion after having been raised unaffiliated, more than four dropped any affiliation.
"Of particular note is a sharp increase in the percentage of Americans who self-identify as atheists and agnostics," said Green, the Akron professor, who's an adviser to Pew. "This trend towards the unaffiliated has occurred among all age groups to some extent and among all the major racial and ethnic communities, as well."
The results were welcomed by atheist and secular humanist organizations.
The nonprofit activist group American Atheists called the study "great news" and tweeted that if you're an atheist, "it's okay to use the word!" And Hemant Mehta, a member of the board of the humanist charity Foundation Beyond Belief and author of "The Friendly Atheist," said: "It's just incredible news all around. It's also a sign that we need to continue speaking out about the problems with religion."
For very different reasons, Russell Moore, president of the Southern Baptist Convention's Ethics and Religious Liberty Commission, is inclined to agree.
"This report actually leaves me hopeful," Moore said.
Moore said the report showed that "people who don't want Christianity don't want the almost-Christianity offered to them by traditions that jettison the historic teachings of the church as soon as they become unfashionable."
In a separate blog post, Moore said the report identified that "we simply have more honest atheists in America" — not necessarily more actual atheists. And that makes his job simpler, he said.
"The gospel comes to sinners, not to the righteous," he wrote. "It is easier to speak a gospel to the lost than it is to speak a gospel to the kind-of-saved."