It's becoming more and more dangerous for preachers to use the words "sex" and "sin" in the same sentence.

Consider this question: Is sex outside of marriage a sin?

Say "yes" and millions of believers who are sitting in pews will say "amen." But that same affirmation of centuries of doctrine will offend just as many believers and nonbelievers, giving them an easy excuse to avoid congregations they believe are old fashioned and intolerant.

"We have to recognize that our historic positions on sexual issues are becoming incredibly distasteful to more people in this culture and especially to our media and popular culture," said Ed Stetzer, director of the Southern Baptist Convention's LifeWay Research team.

"The whole 'Hate the sin, love the sinner' thing -- people are not getting that anymore. People do not believe that we mean that."

Right now, the gay-marriage issue is making headlines. But for millions of traditional believers in Christianity, Judaism, Islam and many other faiths, this issue is linked to a question rooted in religious doctrine, not modern politics. In a spring LifeWay survey, researchers asked: "Do you believe homosexual behavior is a sin?"

The results showed a culture torn in half, with 48 percent of American adults saying that homosexual acts are sinful and 45 percent disagreeing. Considering the margin for error, this is a virtual tie.

The numbers were radically different in different pews, with only 39 percent of Roman Catholics believing that homosexual acts are sinful, as opposed to 61 percent of Protestants and 79 percent of those who identified as evangelical, "born again" or fundamentalist Christians.

A similar pattern emerged from a hot-button question in the latest results reported from the U.S. Religious Landscape Survey conducted by the Pew Forum on Religion & Public Life. Researchers in this massive effort asked participants which of the following statements "comes closer to your own views -- even if neither is exactly right. 1 -- Homosexuality is a way of life that should be accepted by society, OR 2 -- Homosexuality is a way of life that should be discouraged by society."

The question was not stated in strictly political or religious terms. However, with that powerful, more official word "discouraged" in the question, 50 percent of the adults surveyed said that "homosexuality" in general, as opposed to homosexual behavior, should be accepted by society.

Once again, there were sharp differences in various religious groups, with 79 percent of American Jews, 58 percent of Catholics and 56 percent of mainline Protestants calling for acceptance of homosexuality. Meanwhile, only 39 percent of the members of historically black churches, 27 percent of Muslims and 26 percent of the evangelical Protestants affirmed the public acceptance of homosexuality.

These numbers are evidence of great change in the religious and moral views of many Americans, yet they also point toward familiar tensions between traditionalists and progressives. The Pew Forum survey, for example, again demonstrated a reality seen in recent elections. Americans who frequently attend worship services and say that religion is very important in their lives continue to take more conservative stands on hot moral issues in public life.

What about people outside the pews? That is where another set of statistics will prove especially distressing to clergy who sincerely want to defend what Stetzer called the ancient "one man, one woman, one lifetime" doctrine of marriage.

In the LifeWay survey, 32 percent of American adults said that their decision to visit or join a congregation would be "negatively affected" if it taught that homosexual behavior is sin. That number rose to 49 percent among the "unchurched," people who rarely or never attend worship.

The issue of homosexuality does not, of course, stand alone, said Stetzer. It's getting harder for religious leaders to maintain consistent teachings about other acts and conditions that traditional forms of religion have, for centuries, considered sin. This affects preaching on premarital sex, divorce, cohabitation and adultery.

"Ultimately, the modern church has failed to proclaim and explain a biblical ethic of sexuality," he said. "We also need to admit that the church has failed to live out the ethic that it's claiming to be advocating. If we are going to say that we stand for the sanctity of marriage, then we -- in our churches and in our homes -- are going to have to live out the sanctity of marriage."