Romans 6

Should we sin just because we are forgiven? Should we worry about doing the right thing since we are already saved?

These are things that we use to justify our continually sinful behavior and nature. Regardless of whether we are forgiven or saved, nothing has changed in terms of proper behavior. God still expects us to uphold His statutes and strive to cease sinning. Of course, we are forgiven for our sins and God realizes that we aren't perfect, but for us to continue to sin does not represent any change in our heart.

When we are united with Christ, we are no longer slaves to sin. We have the ability to call on the Holy Spirit to assist in times of temptation. Although we can't, by natural means, help but to sin, we can by supernatural means avoid it, and that is part of the learning process. A sinner outside of a relationship with God doesn't realize that anything is wrong. He's always been a slave to sin, so he's just behaving the way that he always has. A Christian is a slave to righteousness, so it's glaringly obvious in his spirit when he has sinned and stepped outside of righteousness.