What does Romans 6:14 mean?

The context of this passage is the spiritual condition of those who are saved. Paul's remarks here are about those who have expressed saving faith in Christ, not to the entire human race (Romans 5:1). Paul concludes his commands to not allow sin to tell us what to do. He again reminds the reader that sin has no authority in our lives any longer. Those without Christ, standing on their own merits apart from God, are compelled to sin. As we once were, they are slaves to sin. Because Christ rescued us, that's not who we are any more. Sin is not the boss of us.

Now Paul adds a surprising thought. We are not under sin's authority because we are not under the law. In some sense, being under the law revealed how powerless we were against our own desires to sin. Instead, Paul writes, we are under grace. Because of God's grace, we are no longer compelled to sin.