For sin shall not have dominion over you, for you are not under law but under grace. (Romans 6:14)
Paul has pointed out that Christians are dead to sin and alive to God (Romans 6:1-14).
This had not been done through the Law of Moses, for the Law could only condemn those who had sinned (Romans 3:23). They had been made alive by the grace of God through Jesus Christ (Romans 5:1-2).
However, God’s grace did not encourage Christians to continue in sin.
The Law could not promote ethical living because it only served to increase transgression (Romans 5:20). Grace is the superior way because God, through His Son, freely provided the way out of sin. As we imitate His life and death, by dying and rising with Him in baptism, we are freed to live ethical lives without the Law (Galatians 2:19). To live under the Law is to live under the dominion and mastery of sin, the very thing Christ came to destroy. - Pollard, Truth for Today Commentary, 214-215
No longer were they under sin - they had been set free from the reign of sin (Romans 6:12).
If they were under law, Sin would be their lord. But they are not under law, they’re under grace and so Sin cannot own them. Sin has been handled! Law has been removed as the ground for acquittal and faith has laid hold on grace. Now they are the Lord’s! - McGuiggan, Romans, 195
We live under a regime of grace which has forgiveness available when we transgress sacred law. - Jackson, New Testament Commentary, 276
If the Law were all we had - we would all be hopeless. All have chosen to sin (Romans 3:23), and the just reward for sin is death (Romans 6:23).
It is by God’s grace that He offers something different to us than what we deserve. His grace sets us free from sin - not to continue to live in sin, but to live a new life in Christ Jesus for righteousness.
I know many folks struggle with this so thank you for sharing.