(CBS SF) — A Salt Lake City businessman and self-proclaimed atheist is making six figures selling the Bible in Apple’s app store.

What started as a small side project with the goal of paying rent turned into a $100,000-a-year business for Trevor McKendrick. The inspiration for kicking off a career in the Bible app industry began two years while at a family dinner. In his blog, he explains he learned that a relative was earning $8,000 to $10,000 a month making apps in Apple’s app store.

READ MORE: KPIX Reporters Remember Slain Security Guard Kevin Nishita; 'Just the Kindest Man'

Intrigued, he began researching what would make a profitable app. He discovered that most of the Spanish Bible apps on the market were poorly designed. He thought among the sparse competition that he could make a better one.

After investing $500 on app development, he launched on Sunday. One month later, he was reeling in over $1,400. Once he expanded the app with an audio version, he was making up to $6,000 a month. By the second year, the app brought in over $100,000 in net revenue.

He may have surpassed his goals of just paying rent with his new business, but he told StartUp podcast host Alex Blumberg he has some guilt about selling a religious book he doesn’t believe in.

READ MORE: UPDATE: News Crew Security Guard Shot in Oakland Dies From Injuries; Photo of Suspect Vehicle Released

“What if you sold ‘Harry Potter’ books or ‘Lord of the Rings’ books, but you told people it was real?” he said. “And you told people if they would just learn how to write spells themselves, they could heal their children? And if you sold that as a real thing? I would feel terrible about that. But that’s really the situation I am in selling the Bible. I am selling this thing I truly believe is fiction.”

He told Blumberg he gets emails sometimes from his app users asking him to pray for them, assuming he’s a preacher. But he said the mounting guilt is not enough to make him back down.

“No I can’t (stop),” he said. “Yes I have a problem with it. But I can’t.”

MORE NEWS: Teenage Programmer in East Bay Creates Internet Study-Buddy Platform for Students