Interfaith marriage is on the rise in America, from 15% of all marriages in 1988 to 36% in 2010. This is true in every region of the country, for people at every income and educational level, and across religious traditions: evangelicals, Jews, Muslims, Mormons, Catholics, and others are increasingly marrying outside the faith.

On the surface, this looks like another triumph of the American melting pot. But that is only part of the story. As Wall Street Journal veteran Naomi Schaefer Riley shows in this provocative book, interfaith marriages are often fraught with peril. People often marry at a time when they have drifted away from their religious roots, and it may seem as if the only relevant question is who will officiate at the wedding. But once couples are married, and especially after they have kids, religious questions reassert themselves. Should we donate to the church? How do we handle holidays? How will we raise the kids? Do we take them to services? Send them to religious schools? These questions, and many others, increase marital tension. Indeed, as Riley shows, interfaith couples report lower levels of marital satisfaction than same-faith couples.

Yet, while an overwhelming majority of Americans claims that religion is important to them, interfaith couples rarely discuss these issues before the wedding. Indeed, many equate religion, the source of their most deeply-held values, with the skin-deep matter of race, believing it bigoted to emphasize shared religious values. As a result, they are often woefully unprepared for the challenges of interfaith marriage.

Drawing on a groundbreaking new national survey of 2,500 Americans and extensive interviews with couples, religious leaders, and marriage counselors, Riley offers readers an intimate look at this sensitive topic that will shape faith and marriage in America for generations to come.