"My mum always said to treat women with respect. For me that was always in my head while I was doing it [being promiscuous], so I could never enjoy it," Bieber said.
"He [God] doesn't ask us not to have sex for him because he wants rules and stuff. He's like, 'I'm trying to protect you from hurt and pain.' I think sex can cause a lot of pain."
Bieber believes he received good karma after having a more pure lifestyle, leading him to marry the love of his life Baldwin.
"I believe that God blessed me with Hailey as a result. There are perks. You get rewarded for good behaviour," Bieber added.
The said revealed that seeing his now-wife in June last year made him realise how much he loved her despite their previous rough break-up.
"When I saw her last June, I just forgot how much I loved her and how much I missed her and how much of a positive impact she made on my life," Bieber recalled. "I was like, 'Holy cow, this is what I've been looking for.'"
Baldwin, who was also in the interview, explained that the horrible comments about their relationship on social media lead to having a lonely first few weeks after they got married.
"I prayed to feel peace about the decision [to get married], and that's where I landed," she said. "I love him very much. I have loved him for a long time."
The couple also revealed that there had been infidelity when they were together the first time around.
"Negative things happened that we still need to talk about and work through," Baldwin explained.
"Fizzled would not be the right word — it was more like a very dramatic excommunication.
"There was a period where if I walked into a room, he would walk out."
Bieber told Vogue: "It's been so hard for me to trust people, I've struggled with the feeling that people are using me or aren't really there for me. One of the big things for me is trusting myself.
"I'm the emotionally unstable one. I struggle with finding peace. I just feel like I care so much and I want things to be so good and I want people to like me."
Baldwin said she's committed to their marriage and acknowledged that taking this big new step will be a challenge.
"I'm not going to sit here and lie and say it's all a magical fantasy. It's always going to be hard. It's a choice. You don't feel it every single day. You don't wake up every day saying, 'I'm absolutely so in love and you are perfect.' That's not what being married is … We're really young, and that's a scary aspect," she admitted.
"We're going to change a lot. But we're committed to growing together and supporting each other in those changes. That's how I look at it. At the end of the day, too, he's my best friend. I never get sick of him."