Justin Bieber Sees Pastor Carl Lentz as Father Figure Now

Justin Bieber won't complain about one part of his life on the road -- it forced him to grow incredibly close to his pastor, Carl Lentz ... so much so, he now sees him as a 2nd father.

Sources close to Hillsong Church tell TMZ ... Lentz stepped up big-time as a guiding presence in Justin's life, especially while he was on the road and overseas. We're told Justin was lonely during most of the Purpose tour -- he's been estranged from his mother, and likewise, had no relationship with his dad, Jeremy, for some time now.

On the flip side, Lentz flew to visit Justin often -- particularly during his Australia and New Zealand tour stops in March, then they kicked it again during his April break in NYC ... where Pastor Carl primarily preaches.

Interestingly, sources at the church tell us Justin and Carl have spent almost every day together within the last month, and one source described them as "nearly inseparable." As we reported, Justin also views Hillsong as an escape from his celebrity life.

His fondness for Carl, and vice versa, is obvious in a Hillsong Church video posted a few days ago.