The Canadian singer, who became famous when he was 13, shot to fame quickly after being discovered and, despite huge popularity, also got much media criticism for the mistakes he made in his youth.
He acknowledged in his post that he had a lot of money, clothes, cars and awards but says he was not satisfied and felt an enormous burden, saying: "when you add the pressure of stardom it does something quite unexplainable to you".
He described how his world was "flipped on its head" and he was being "praised left and right by the world with millions saying how much they loved me and how great I was".
However, he admitted that he started doing drugs at 19 and "abused all of my relationships...became resentful, disrespectful to women, and angry."
The celebrity, who now attends a Hillsong church and is married to model Hailey Baldwin, added: "It's taken me years to bounce back from all of these terrible decisions, fix broken relationships, and change relationship habits. Luckily god blessed me with extraordinary people who love me for me.
"Now I am navigating the best season of my life MARRIAGE!!" which he said was teaching him "patience, trust, commitment, kindness, humility and all the things it looks like to be a good man".
He concluded: "even when the odds are against you keep fighting. Jesus loves you...LOVE PEOPLE TODAY NOT BY YOUR STANDARDS BUT BY GOD'S PERFECT UNFAILING LOVE".
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