Sarah Garrison grew up Catholic, but today she does not consider herself part of any religion. Yet as someone who meditates and prays every day to the "God here in our hearts," she would never call herself an atheist or agnostic and thinks church can play a positive role in society and individual lives.

"Some people need [religion]," said Garrison, 26, who works as a training coordinator for an online news company in Moline, Ill. She mentions her older sister, a Catholic nun, who "couldn't be happier" with structured religious practice.

According to a new report from the Pew Forum on Religion and Public Life, Garrison has plenty of company in her spiritual beliefs and practices.

One in five American adults now have no religious affiliation, according to the report released Tuesday. They include self-described atheists and agnostics, but also a much larger number of people who have no interest in labeling themselves in any way when it comes to their faith or lack thereof. The group, which the report also called the "nones," has shot up to 19 percent from 15 percent of American adults in a Pew survey five years ago.

The latest Pew report, which used data from a summer survey of the nones and crunched numbers from earlier Pew surveys, found there are 46 million religiously unaffiliated adults in the U.S., including 13 million self-described atheists and agnostics and 33 million people who don't identify with any religion. More than two-thirds of the nones said they believe in God, more than half said they frequently feel a deep spiritual connection with nature and the Earth, more than one-third see themselves as "spiritual but not religious," and one in five pray daily.

Describing the findings to reporters ahead of the survey's release, Pew senior researcher Greg Smith said the growth in nones can be largely attributed to the gradual replacement of older, generally more religious generations with younger, generally less religious generations.

The survey found that one-third of adults under 30 do not see themselves as members of any religion, compared to one in 10 among people 65 and older.

"Young people are also more likely to be nones than previous generations were at similar stages in their lives," said Smith.

"People are not looking for religion. They are not seekers," added Pew senior researcher Carey Funk. "When we asked people who describe their religion as 'nothing' whether they were looking for religion, only 10 percent said they were," she said.

But most of the nones said they believe churches can do good in society by bringing together communities and helping the poor, according to the report. A significant majority of the nones also believe that religious institutions are too focused on money, power, rules and politics.

"The rise of the nones [coincides] with the fall of American Protestantism," said Smith. He noted that for the first time since Pew begin conducting religion surveys, fewer than half of Americans (48 percent) now identify as Protestant.

To be sure, the U.S. is still one of the most religious developed nations. The number of Americans who say religion is very important in their lives (58 percent) is double that of many European nations.

Moreover, the decline in the number of Protestants may be less about people dropping out than it is about Americans changing the way they talk about religion. In a 2007 Pew survey, 60 percent of people who said they seldom or never attended religious services still described themselves as being part of a specific religious group. Tuesday's report indicated that people are now more comfortable describing their religion in terms that match their practice, with a 10 percent drop in the number of people who identify with a denomination but seldom or never attend services.

Smith said the Protestant decline has occurred largely among whites, both evangelical and mainline, while the number of non-white Protestants has remained steady. The number of U.S. Catholics has remained stable because of immigration from Latin American nations. In 2012, 21 percent of adults identified as Catholic, compared to 22 percent in 2007.

The recent increase in the number of nones has taken place across income levels, education levels and gender, the report said.

While the aging of a younger generation has led the growth, the report also found that older generations have increased their number of religiously unaffiliated. In 2012, 21 percent of Generation Xers and 15 percent of baby boomers called themselves unaffiliated, while five years ago those figures were 18 and 12 percent, respectively.

Looking at exit polls from presidential elections, the Pew report found that Democratic candidates have won an increasingly high percentage of votes from the religiously unaffiliated. In 2008, 75 percent of the nones registered to vote went for Barack Obama. The report found the unaffiliated to be liberal on social issues, with a majority supporting same-sex marriage and legal abortion. Yet on the role of government, the nones are only slightly more likely than the general population to favor a bigger government that provides more services over a smaller government that provides fewer services.

John Green, a political science professor at the University of Akron in Ohio, said the rise of the nones could have a significant impact on the political landscape.

The religiously unaffiliated, he said, "may be becoming the single largest faith-based or religious group, larger than African-American Protestants, larger than Catholics ... It may be in the near future that the unaffiliated vote will be as important to the Democratic Party coalition as the traditionally religious are to the Republican Party coalition."

Click through to see most and least religious states in America (via Gallup):
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  • #1: Mississippi (59 percent)

  • #2 Utah (57 percent)

  • #3 Alabama (56 percent)

  • #4 Louisiana (54 percent)

  • #5 Arkansas (54 percent)

  • #6 South Carolina (54 percent)

  • #7 Tennessee (52 percent)

  • #8 North Carolina (50 percent)

  • #9 Georgia (48 percent)

  • #10 Oklahoma (48 percent)

  • #51 Vermont (23 percent)

  • #50 New Hampshire (23 percent)

  • #49 Maine (25 percent)

  • #48 Massachusetts (28 percent)

  • #47 Alaska (28 percent)

  • #46 Oregon (30 percent)

  • #45 Nevada (30 percent)

  • #44 Washington (30 percent)

  • #43 Connecticut (31 percent)

  • #42 District of Columbia (32 percent)

  • #42 New York (32 percent)

  • #42 Rhode Island (32 percent)