What does Romans 7:20 mean?

Paul repeats almost exactly what he wrote in verses 16–17. He clearly wants to make sure his readers understand what he is saying. He paints a picture once more of a battle between his good intentions and the sin that lives in him. He describes his intentions as wanting to do good, to follow the law of Moses, to obey God. That's the "real him." The sin in him, though, wins out over his best inclinations.

Some Bible scholars believe Paul to be describing his life before becoming a Christian, when he lived as one of the Jewish religious leaders. That makes sense in light of his larger point that simply wanting to follow the law of Moses does not save anyone because nobody succeeds. Everybody still sins.

Other scholars understand Paul to be describing his experience with sin as a Christian. They insist that while it's true Paul had been freed from slavery to sin (as all Christians are), he continued to experience the powerful temptation to sin (as all Christians do). This also makes more sense of the Greek language Paul uses here, which has shifted into a first-person, present-tense, singular perspective, one quite different from his prior words.

Whichever Paul meant to communicate, both positions have merit. Non-Christians may very well have the desire to obey God, but Paul has taught in Romans that without Christ we do not have the ability to keep ourselves from sinning. It's also true that Christians, while never under obligation to sin, often "catch themselves" in the act of doing the exact opposite of the good thing they set out to do. They continue, on some level, to feel divided between their desire to sin and their desire to serve God.