Tony Campolo has been a fixture in the evangelical Christian scene for decades. For the past 30 years his son, Bart has followed in his footsteps. Their brand of Christianity is evangelical (personal salvation through Jesus) but with an emphasis on social justice and care for least of these.

Just over two years ago, Bart decided to tell his parents that he no longer could believe in God. Out of this painful and liberating revelation is their story, the film, Far From the Tree, and the book, Why I Left: Why I Stayed: Conversations on Christianity Between an Evangelical Father and His Humanist Son.

Bart is still in ministry. It isn’t Christianity, however. He is the University of Southern California’s first Humanist Chaplain. He speaks with me about what happens in many families when religion divides. Many families stop talking. The Campolos keep the conversation going.