Justin Bieber has declared it's "time to grow up".

The 30-year-old pop star - who is married to model Hailey Bieber, 28, and has six-month-old son Jack - shared a cryptic post on his Instagram page in which he admitted he is "not good" at following rules but he's determined to embrace a "life of love" as he follows his Christian faith.

Justin wrote: "It's time to grow up. Changing is about letting go! Not trying harder! Are you tired of trying to follow all of the rules in hopes to get the results you crave? I've found love to be more powerful than rules."

He added: "I tried to follow the rules. I'm not good at it. But u don't need to follow rules to enter into a life of love. U just receive so enter love living! God always grants us love! It's one of his promises! Upon receiving God's love! U start to change and start following love."

It comes after Justin sparked concern among his fans by unfollowing his wife Hailey on Instagram - with the singer later claiming the issue was caused by a hacker infiltrating his account - and being pictured leaving a spa in Los Angeles without his shirt on.

However, an insider recently insisted the pop star is "happier than he has been in a long time".

A source told UsWeekly: "Justin is a happy camper right now, he's happier than he's been in a long time ...

"There's no breakdown, and he just really doesn't care what people think. He knows he looks strange leaving spas shirtless, but it's just him.

"And after the rumors he's doing it out of spite now, he's just being himself and won't create a squeaky clean image just because the public wants him to."

Justin and Hailey married in 2018 and they welcomed their first child, son Jack, last year.