c. 2013 Religion News Service

WASHINGTON (RNS) Nearly two-thirds of Americans believe legalized same-sex marriage in the U.S. is inevitable, according to a study by LifeWay Research, a Nashville polling firm with ties to the Southern Baptist Convention.

    But for some respondents, inevitability doesn't equal approval.

    According to the findings, 64 percent of American adults believe same-sex marriage will become legal, whether or not they believe in it.

    "We're kind of in a national conversation about not just the issue of marriage and homosexuality, but really how our culture responds both to shifting views on the issue and views that aren't shifting," said Ed Stetzer, the president of LifeWay Research.

    According to a poll from last November, by the Pew Forum of Religion & Public Life, 48 percent of Americans support same-sex marriage, up from 35 percent in 2001. A Gallup poll last December showed that 53 percent of Americans support gay marriage.

    Christians, however, are split on their support of gay marriage. Only 19 percent of white evangelical Protestants favor gay marriage, according to the Pew poll; Catholics are the most in favor of same-sex marriage among Christian groups, at 54 percent.

    Fred Sainz, vice president of communications for the Human Rights Campaign, said gay marriage is no longer a question of if, but when. "These are no longer assertions, they're verifiable conclusions," Sainz said.

    But not everyone agrees that same-sex marriage is a sure thing.

    Ryan Anderson, a fellow of the conservative Heritage Foundation, said that not everyone understands the issue, which means they can't be certain.

    "There hasn't been effective articulation for the case, for traditional marriage. We're just now having a national conversation of what marriage is," Anderson said. "No one knows what the consequences of redefining it are."

    Nine states and the District of Columbia have already legalized gay marriage, and the Illinois Senate recently passed a bill to do the same. In addition, 11 other states allow civil unions or domestic partnerships.

    The LifeWay poll also found that a majority -- 58 percent -- of respondents believe gay marriage is a civil rights issue.

    The survey asked people whether various individuals or companies should be able to refuse services to same-sex couples. Sixty-three percent said clergy should be allowed to say no, and 58 percent said the same for photographers. Minorities of Americans believe that rental companies (40 percent), landlords (20 percent) or employers (14 percent) should be allowed to discriminate against gay couples.

    There are currently no federal laws that prohibit discrimination based on sexual orientation. However, 21 states and the District of Columbia have laws that prohibit employment and housing discrimination based on sexual orientation.

    The issue of same-sex marriage will come to a head later this month, when the Supreme Court hears arguments against California's Proposition 8 that banned gay marriage and the 1996 Defense of Marriage Act, which prohibits the federal government from recognizing gay marriages.

    The LifeWay poll of 1,191 U.S. adults has a margin of error of plus or minus 2.9 percentage points.