The leader at Hillsong New York has been supporting the 21-year-old over the past year. Bieber regularly posts pictures of him and the pastor as well as quotes from his sermons.
They're both currently attending the Hillsong Conference with around 20,000 others at the Allphones Arena in Sydney.
While Pastor Lentz was being interviewed there by a local TV network, the Canadian pop star is reported to have jumped on screen and said "I'm glad to know him. He's changed my life".
Conference host Brian Houston has been talking about Justin Bieber's appearance at the Hillsong Conferemce.
In an interview with Nine Network TV, he said: "I think a lot of things got the better of him, like happens with young kids.
"No doubt he'd probably be the first to say he lost his way in a whole lot of ways and, yeah, I think he realises that it's now-or-never time to try to build better foundations into his life."