Americans' support for legalized same sex marriage has jumped 21 percentage points, from 32 percent in 2003 to 53 percent in 2013, with more religious groups now supporting allowing gay people to wed a new survey finds.

The new national survey of more than 4,500 respondents conducted by the Public Religion Research Institute found that while most religious groups opposed same-sex marriage in 2003, today there are religious groups on both sides of the issue.

There is now a big divide between evangelical Protestants who strongly oppose same sex marriage and adherents of other Christian faiths who mostly support it.

The years 2003 was when Massachusetts became the first state to legalize marriage between gay and lesbian couples. In that year all major religious groups opposed same-sex marriage, with the exception of the religiously unaffiliated.

One of the findings of the survey was that regular churchgoers (those who attend at least once or twice a month), particularly those who belong to religious groups that are supportive of same-sex marriage, are likely to underestimate support for same-sex marriage in their churches by 20 percentage points or more.

Today religiously unaffiliated Americans (73 percent), white mainline Protestants (62 percent), white Catholics (58 percent), and Hispanic Catholics (56 percent all favor allowing gay and lesbian couples to marry.

A majority (83 percent) of Jewish Americans also favor legalizing same-sex marriage.

Hispanic Protestants are divided; 46 percent favor allowing gay and lesbian couples to legally marry and 49 percent oppose.

EVANGELICAL PROTESTANTS

By contrast, nearly 7-in-10 (69 percent) white evangelical Protestants and nearly 6-in-10 (59 percent) black Protestants oppose same-sex marriage. Only 27 percent of white evangelical Protestants and 35 percent of black Protestants support same-sex marriage.

At the same time the survey found that churches teachings on same-sex relationships that strongly oppose them can drive young people away from the religious institutions.

"While many churches and people in the pews have been moving away from their opposition to LGBT rights over the last decade, this new research provides further evidence that negative teachings on this issue have hurt churches' ability to attract and retain young people," said PRRI CEO. Robert P. Jones.

"Nearly one-third of Millennials who left their childhood religion say unfavorable church teachings about or treatment of gay and lesbian people played a significant role in their decision to head for the exit."

The Week magazine of February 27 is, however, dismissive of this analysis that suggests Millennials are less religious because of gay marriage

"It's no secret that young Americans aren't as religious as their elders." Joe Terbush writes in The Week noting that the PRRI survey suggests that part of that rift may be attributed to a perceived anti-gay bias in organized religion.

He notes one of the PRRI survey findings that among those who have abandoned their childhood religion and are not affiliated to any religion, 25 percent say anti-gay teachings factored into their decision to go faithless. Further among Millennials who have turned irreligious, almost one third said the same.

"At first blush, that would appear to suggest clear causation: stuffy old anti-gay religious dogma is spooking all the hip youngsters."

While Terbush writes that there is link between the two, he says the survey's analysis is over simplistic as it does not devote enough attention to why Americans, and especially younger ones, are shunning religion.

He notes that the PRRI's survey results find that for 31 percent of Millennials who are no longer religious anti-gay teachings were a factor in their decision only 14 percent called it a "very important" reason for having no faith. Conversely fully two thirds of Millennials who abandoned religion said their decision had very little or nothing at all to do with religion's position on homosexuals.

Terbush cites a 2012 Pew survey that finds Americans have been growing less religious for some time now. This found that about 20 percent of Americans were either atheist, agnostic, or religiously unaffiliated, categorizing that demographic as the "nones."

And young adults have less faith than any other age bracket; nearly a third of them are religiously unaffiliated. Notably, they are also less religious than previous generations were at this point in their lives.