Canadian pop star Justin Bieber used to party hard, drink booze without limits, and make the headlines more for his crazy antics than his music. But he gave up his old life when he re-committed his life to Jesus Christ.

Bieber got his life on track, and his pastor, Carl Lentz, told Us Magazine that the "Love Yourself" singer's faith has grown exponentially since they first met.

"I think Justin has a really deep, mature relationship with Jesus. I don't think my teaching or my preaching has made even remotely as big of an impact as his own desire and passion and love for Jesus. That's how it should work," he said. The primary change agent in somebody's life, it shouldn't be a person. It shouldn't be a preacher. It should be God."

It is for this reason that Lentz said Bieber is not so much dedicated to Hillsong Church as to God and his life as a Christian, and that he has worked hard to make positive changes in his life. "I think all his changes are a credit to him and him allowing God to continue to use him. Nobody gets credit for that," Lentz said, adding that he is continuously inspired by the singer's spiritual journey.

Lentz recently released his self-help book, "Own the Moment," according to Radar Online. In it, he talked about his friendship with Bieber and how down to earth the singer actually is in real life.

"People always ask, 'What's it like talking about life and Jesus with Justin Bieber?'" Lentz wrote in the book. "I always say the same thing: 'Matter of fact, he's just like you. And just like me.'"

Lentz said that although things are certainly different on a "money level," there is one thing that he and the pop star has in common - "what it's like to be lonely. What it's like to want to grow in areas that are hard to talk about. What it's like to be disappointed. What it's like to make mistakes that affect people we love."