4 Now to the one who works, wages are not credited as a gift but as an obligation. 5 However, to the one who does not work but trusts God who justifies the ungodly, their faith is credited as righteousness.
The justified believer is declared to be free of the demands of the law since they have been fulfilled in Christ and they are no longer subject to the penalty of the law. They are justified, set right by God, and placed in a right relationship with Him, just as if they had not sinned. Our relationship with God was a legal relationship but now it is parental. He is now our heavenly Father and as His children we are given His righteousness by faith.
6 For we know that our old self was crucified with him so that the body ruled by sin might be done away with, that we should no longer be slaves to sin— 7 because anyone who has died has been set free from sin.
Notice it says, “we should no longer be slaves”, that means we have the ability in Christ, not to be slaves to sin. We are Christians who are justified by Christ, who have the ability in Him, to say no to sin.
3 For what the law was powerless to do because it was weakened by the flesh, God did by sending his own Son in the likeness of sinful flesh to be a sin offering. And so, he condemned sin in the flesh, 4 in order that the righteous requirement of the law might be fully met in us, who do not live according to the flesh but according to the Spirit.
As Christians, we can choose to live according to the Holy Spirit and say no to the flesh. The problem is sometimes we want to sin because we are not living according to the Spirit.
1 Corinthians 10:13
13 No temptation has overtaken you except what is common to mankind. And God is faithful; he will not let you be tempted beyond what you can bear. But when you are tempted, he will also provide a way out so that you can endure it.
Because we are declared righteous by God we don’t have to give in to sin.