City Church pastor Judah Smith, also known as pastor to Justin Bieber, has said that he is proud of the young singer and admires his ability to pick himself up and start afresh.

Bieber, who has just turned 21, apologised earlier this week for his recent behaviour, which has resulted in several run-ins with the law.

"I've turned a lot of people off in the last few years. But I know I can still put out good music and turn everything all around," Bieber said.

Smith said in an interview with PEOPLE magazine this week: "It's astounding to consider that at such a young age he's experienced extraordinary fame, and yet here he is at 21 years old making some amazing decisions and really developing. I'm proud of who Justin is and the incredible journey he's on."

The Seattle-based megapastor has often spoken about his close relationship with Bieber, who is one of a number of celebrities who have attended City Church.

He said in an interview with FOX411 last week that it was not easy for young celebrities to make good life decisions.

"I think what's amazing about Justin and many young men today, it's not easy to be a man of faith, it's not easy to make good decisions, there are a lot of options in our modern culture and modern society, particularly when things are afforded to you on a celebrity status. But Justin certainly loves God and is passionate about being the man that he wants to be."

In September, the pop star pled guilty to misdemeanour charges of careless driving and resisting arrest in Miami, and he pled no contest to vandalism in July after egging a neighbour's home in LA. Accusations of interfering with a flight crew during a Super Bowl trip in January 2014 were dropped, as well as charges that Bieber assaulted a limousine driver in December 2013.

But Smith told Fox that he admired Justin for "the ability to take every day at a time. To recognise that if you faltered yesterday... all you can do today is pick yourself up, put one foot in front of the other, take it a day at a time. I think that's what Justin is attempting to do, that's certainly what I'm trying to do."

Smith added that his new book 'Life Is ____', released this month, addresses the idea that although money and fame are ok, they cannot ultimately satisfy.

The book seeks to inspire readers to discover the love story in the Bible, not just a moral code. Smith wants people enjoy God to the fullest, trust God and be at peace with God, themselves and with others.