Overcome Temptation

"Colossians 2:13 rocked my world a long time ago and still rocks my world today. "And you, who were dead in your trespasses and the uncircumcision of your flesh, God made alive together with him, having forgiven us all our trespasses..." I wanted to believe that Jesus forgave my sins, but I just wasn't sure. * How do I overcome my addiction to marijuana? * Were we ever part of the Old Covenant? Were we ever "under the law"?​Were we redeemed from the curse of "the law"? * Yes I know the Lord has forgiven me... but that doesn't mean I can continue to sin... am I correct?