What does Romans 3:8 mean?

Paul finally gets to the heart of one reason for the question-and-answer format he has been using. He is answering the slanderous charges of some of his accusers. Because Paul teaches that human sinfulness demonstrates God to be completely righteous—because He remains faithful even when we do not—they have been saying that Paul is telling people to keep sinning. Paul calls this for what it is: slander, a deliberate, dishonest lie meant to damage his reputation and his efforts.

These critics go so far as to say that the logical outcome of Paul's teaching is to provoke people to sin more to make more good: "Why not do evil that good may come?" Paul has described this as a human argument (Romans 3:5). It clearly does not make any sense. It sounds like the twisted logic of a condemned man trying to talk himself out of punishment he has earned.

In fact, this is such a foolish idea that Paul doesn't even bother to debate it, at least not now. The fact that God remains righteous and faithful in the face of human sinfulness does not mean that God wants humans to sin more. It means that He is being consistent to His own nature.

Instead of arguing the point further, Paul simply says this of those who are accusing him of telling people to go on sinning: "Their condemnation is just." In other words, they have earned God's wrath. He will return to a more detailed look at this challenge, later in this letter (Romans 6:1).