“I believe that I cannot by my own reason or strength believe in Jesus Christ, my Lord, or come to him; but the Holy Ghost has called me by the gospel, enlightened me with his gifts, sanctified and kept me in the true faith.”

Most of my Facebook friends are clear about their religious views. They identify as Lutheran, Catholic, or atheist…My cousin tells her online friends, “I’m spiritual, not religious … and I enjoy checking out European cathedrals.”

She’s not alone. The number of people who self-identify using the long-popular phrase “spiritual but not religious” is still growing. In 1998, 9 percent of American adults told the General Social Survey they were spiritual but not religious. By 2008, it had risen to 14 percent. Among those ages 18 to 39, the increase was even more dramatic, and 18 percent now say they are spiritual but not religious.

The growth is not because people are less likely to identify as religious, but because nonreligious people are more likely to say they are spiritual, says Duke sociologist Mark Chaves.

Part of the phrase’s popularity can be attributed to its sex appeal. No, really. A social psychologist at Britain’s Southampton University looked at 57 studies covering 15,000 experiment subjects, and reported in Personality and Social Psychology Review that North Americans find “intrinsically religious” people desirable—but that the desirability decreases if people portray themselves as extrinsically religious.

Elaborate dating scheme or not, if you wonder what the phrase means, you’ll probably get a different answer from each person you ask. That may be the point.