Did Jesus Christ ever have an erection? John Marks poses that question to his Christian friend Craig Detweiler in the film Purple State of Mind, which is showing in limited release and available on DVD (see www.purplestateofmind.com). As the title suggests, the film is about what happens when red-state and blue-state types mix it up. Marks and Detweiler were college roommates in 1982, the year Detweiler converted to Christianity and Marks, a cradle Presbyterian, turned into a religious skeptic. Both have since launched media careers—Detweiler as a filmmaker and theologian at Fuller Seminary, Marks as a writer and producer for 60 Minutes, now working independently. As one might expect, the film is snappily produced. It also has spectacular music and crisp editing that captures the friends’ vulnerability and humor.

What makes the film compelling is the honesty of the conversation. Marks asks Detweiler how Christians can avoid being blind to the suffering of the world, since they are keeping their noses in the Bible instead of surveying the particularity of the world. Detweiler shoots back that Marks’s refusal to grant Jesus lordship over his life means that he will have some other lord, since everybody has to serve somebody. Marks says that’s not true: one can create a personal set of beliefs without subscribing to any one faith.

Marks reminds Detweiler of an episode his friend had forgotten—when the new convert had told the new skeptic that “God doesn’t like artists—they ask too many questions.” Detweiler, embarrassed by this reminder of arrogance and struck by the irony that he is now an artist, apologizes.

There is emotional poignancy in these conversations, but also a certain sophomoricness. Detweiler is often too quick to grant the premises of Marks’s critical questions, agreeing, for example, that the church has been the cause of untold suffering and that Christians usually get politics wrong. Detweiler responds to these blanket judgments with more patience than perhaps they deserve. But the strength of the film is the way it is rooted in a friendship that has grown wiser with age. Would that more adults beyond their college years would have friendly, no-holds-barred conversations with those they disagree with.