The fastest growing "religious" group in America is made up of people with no religion at all, according to a CNN report and a Pew survey showing that one in five Americans is not affiliated with any religion.
According to the survey, 33 million Americans now have no religious affiliation, with 13 million in that group identifying as either atheist or agnostic.
Pew found those who are religiously unaffiliated are strikingly less religious than the public at large. They attend church infrequently and are largely not seeking out religion. They also say that the lack of it in their lives is "of little importance."
Pew also found that 68% of the religiously unaffiliated say they believe in God, while 37% describe themselves as “spiritual” but not “religious.” One in five said that they even pray every day.
John Green, a senior research adviser at Pew, breaks the group classified as "religiously unaffiliated" into three groups.
First Green says there are those who were raised totally outside organized religion. Second are groups of people who were unhappy with their religions and left. The third group, Green says, comprises Americans who were never really engaged with religion in the first place, even though they were raised in religious households.
According to the poll, 88% of religiously unaffiliated people are not looking for religion.
Demographically, the growth among the religiously unaffiliated has been most notable among people who are 18 to 29 years old.
According to the poll, 34% of “younger millennials” - those born between 1990 and 1994 - are religiously unaffiliated. Among “older millennials,” born between 1981 and 1989, 30% are religiously unaffiliated: 4 percentage points higher than in 2007.
Poll respondents 18-29 were also more likely to identify as atheist or agnostic. Nearly 42% religious unaffiliated people from that age group identified as atheist or agnostic, a number far greater than the number who identified as Christian (18%) of Catholic (18%).
Read more about the study at www.pewforum.org.
CNN contributed to this report.