Are churchgoing Christians really succumbing to culture creep?

A couple’s sexual history is tied to their happiness in marriage, researchers with the National Marriage Project at the University of Virginia said Tuesday.

That may sound like common sense, but culture claims it’s perfectly normal for sex to come first, before a relationship. Psychologists Galena K. Rhoades and Scott M. Stanley followed 1,000 then-unmarried people for five years, beginning in 2007, and probed the personal histories of the 418 people who got married during that time.

“Actually, what people do before marriage appears to matter,” they concluded.

Rhoades and Stanley say their data contradict the notion that “what happens in Vegas stays in Vegas.” Past sexual relationships have consequences, which appear in couples’ self-reported happiness. That’s consistent with past research, including analysis from the Family Research Council, finding the number of lifetime sexual partners corresponds to divorce.

Stability used to be the norm, the researchers note. “Courtship led to marriage, which led to sex, cohabitation, and children,” they wrote. “Today, marriage comes near the end of the line.”

Those cultural changes are having an effect on society, where more children are growing up in unstable homes. They’re also having an effect on the church, where changing attitudes toward marriage and sexual ethics are seeping into the sanctuary, according to a new study by sociologist Mark Regnerus. But culture’s influence is not as pervasive as some fear. Christians are more likely to adopt cultural attitudes if their ties to the evangelical church and orthodox teachings are tenuous.

“Churchgoing Christians who support same-sex marriage are more likely to think pornography, cohabitation, hook-ups, adultery, polyamory, and abortion are acceptable,” the University of Texas professor said recently.

Regnerus first unveiled his “Relationships in America” survey in April at a leadership summit held by the Southern Baptist Convention’s Ethics & Religious Liberty Commission (ERLC). The survey’s official roll-out is in September. What makes the 16,000-person sample unique is the demographics, which include church attendance. That has allowed Regnerus to map the attitudes of nominal and more-committed Christians in various denominations.

In his latest essay, Regnerus looked at church-going Christians who support and oppose same-sex marriage, along with self-identified gay and lesbian Christians and non-Christians. He found that more than one-third of church-going Christians who support same-sex marriage also are OK with pornography, cohabitation, casual sex, and abortion (see the full table).

Among those who oppose same-sex marriage, fewer than 11 percent support those behaviors. And even on issues that few support, five times as many same-sex marriage supporters think adultery could be permissible and 13 times as many have no issue with polyamorous relationships.

On every question of sexual ethics, Christians who support same-sex marriage had views nearly identical to those of the mainstream culture, Regnerus found.

When Regnerus’ full study is released, it will shed light on everything from porn use to sex within marriage. Not all the news is bad. Christians who affirmed marriage and a more biblical sexual ethic outnumbered those who did not nearly 3 to 1.

And at the ERLC, Regnerus countered the claim that the Church is losing its young people. While those between 18 and 39 years old often are seen as hopelessly liberal, only 11 percent of young evangelicals who regularly attend church support same-sex marriage. Only 5 percent support cohabitation. And fewer than 1 percent of American young people are committed to ever-shrinking liberal denominations.