Why do some Christians turn away from sinful behavior and clean up their act, or try to, while other Christians think it’s okay to continue sinning because they are already saved? I hope you can shed some light on this matter for me.
I don’t know of any true believer who thinks it’s OK to sin. While we all do it, and none of us can stop doing it, we all have the Holy Spirit within us who convicts us of our sins, making us feel bad about them. His intention is to draw us to God in confession so we can be forgiven and feel better (1 John 1:9).
Out of pride or fear, we may resist for a while and when we do we wind up carrying enormous burdens of guilt instead. Our friends and family often don’t see the effects of our internal struggles, but sooner or later all of us feel bad enough about our sins to ask the Lord to forgive us. And as soon as we do, He takes all of our guilt away and everything’s fine again. He can do this because He already knew about all of our sins and paid the penalty for every one of them when He went to the cross (Colossians 2:13-14).