What does Romans 7:18 mean?

Is Paul presenting himself as he was before he came to Christ, back when he was trying to follow the law of Moses as a good Jewish person? Or is Paul describing his experience as Christian who has been freed from sin (Romans 6:2, 18, 22)? Bible scholars disagree about Paul's intent. The specific Greek tenses and words Paul uses here, however, strongly suggests that this is a personal, present, and literal struggle.

In either case, Paul's struggle with sin has brought him to make a blunt declaration: He has learned that nothing good lives in his flesh, his unspiritual mind and body. As a physical human being, good does not come out of him, no matter his best effort.

Why would Paul say such a thing? He has observed the pattern in himself over and over again. He wants to do the right thing. He is sincere. Still, he ends up doing the sinful thing he hates. He has accepted the fact that he, on his own, is not source of what he calls "good." He has the desire, but not the ability, to do what is right.

This fits with what Paul has said about those who are under the law. Their attempt to follow the law reveals to them that they are unable to keep the law, that they are truly slaves to sin.