. >> author david kinman has studied this phenomenon. 8 million millennials give up on god by their 30thpeople who grow up in a christian home are going to walk away on some level. they're either going to become ex-christians or dechurched. ♪ >> david gormley struggled for years and at 16, gave up on god. >> i actually came out as an atheist. i didn't want to lie to people anymore. i was just tired of pretending that i was someone that i wasn't. >> david's news rocked his deeply faithful family. do you remember how they took it? >> with quiet silence at first. for about six months afterwards, we had a very rough period. tensions were just very high. >> take me back to that moment where david said, i need to tell you something. i don't believe in god. >> i guess to hear him say it, to verbalize it was kind of shocking. but it wasn't in the sense that we knew that he had never come to christ. >> this is deep water for us. to see your own flesh and blood pursuing a life of rebellion against god. it's a constant burden to our hearts. >> alienated from friends and family, david finally found