AceShowbiz - Justin Bieber has ditched his cell phone while imposing strict "boundaries" on his professional life.

The 27-year-old singer now only communicates with his team via iPad in order to limit the number of people who can get in touch with him, and he makes sure he stops working by 6 pm in order to spend the evenings with his wife, Hailey.

"I definitely learned how to have boundaries, and I just don't feel like I owe anybody anything," he tells Billboard.

"That has helped me to be able to just say no and just be firm in it and know that my heart (wants) to help people, but I can't do everything. I want to sometimes, but it's just not sustainable."

The "Yummy" hitmaker has made other changes to his life, including attending therapy regularly and reconnecting with his faith.

"I just changed my priorities so that I didn't (become) another statistic of young musicians that ended up, like, not making it," explains Justin.

Justin now wants to use his fame and his music to "inspire" other people, adding, "There was a time where I really did have my identity wrapped up in my career, but I really do have an overflow of feeling like my purpose is to use my music to inspire..."

"I just want to be somebody who can say, 'Look, I did some things that I'm not too proud of, but I took a look in the mirror and decided to make some changes, and you can too.' "

The changes the "What Do You Mean?" singer has implemented in his life have been welcomed by his management team.

SB Projects president Allison Kaye, who co-manages Justin with Scooter Braun, said, "This is a kid who I used to have to beg to go to a rehearsal."

"We used to have to take his computers away or put someone outside his door so he couldn't sneak out."

"He's not even becoming a boss - he's becoming a leader. It's such a beautiful thing to see out of someone whom you've known since he was, like, 12."