Romans 3:8

Why not say—as we are being slanderously reported as saying and as some claim that we say—"Let us do evil that good may result"? Their condemnation is deserved.

(v8, NIV)

This is the last point in Paul's unveiling of their contradiction. Based upon what the objectors have just said, this leads to the conclusion that we should all just continue in sin. Since the judgment of sin leads to the glorification of God, then we should sin so that God would be even more so glorified. However, this does not make sense. There is clearly a flaw in the argument if it leads to the conclusion that we should all just continue in sin. Paul is not saying this and this is what they are saying. What they are saying in their objection and trying to show that Paul is contradicting himself has a contradiction itself. We are not in any way to justify our actions to lead us to continue in sin. If we do in fact sin, God's judgment upon us is just and brings him glory. However, that is not a reason or an excuse to continue in sin. His objectors would agree that we should live according to God's word and live in righteousness. The Jews who had the law and boasted in it were all about avoiding sin. So, if what they are calling Paul out on leads to the conclusion that we should continue in sin, then they are contradicting themselves.