Joshua Harris, one of the most influential voices on sex and relationships for a generation of evangelical Christians, announced this past week that he and his wife are separating after 20 years of marriage.

Harris' book, I Kissed Dating Goodbye, was published in 1997 when he was in his early 20s. It became a manual for young evangelicals looking for love.

In recent years, Harris has apologized for some of the ideas he promoted and publicly wrestled with them in a documentary. In an interview with NPR last year, Harris talked about going through that process with his wife, Shannon.

"I think it's made us realize how there's heartache and there's pain no matter which pathway you choose in life," Harris said. "There's no path that you can choose that can protect you from that."