Romans 3:4 meaning

Once again Paul appeals to the Scriptures, which is what he is referring to when he says, as it is written. Paul quotes from the scriptures: "That you may be justified in Your words, And prevail when You are judged" (v 4).

The Scriptures at the time of Paul was what we call the Old Testament, and this quote is from Psalm 51:4. Psalm 51 is a Psalm of King David written after Nathan the prophet confronted David for committing adultery with Bathsheba (2 Samuel 11:1-5). In this passage, David is pouring out his heart to God asking for forgiveness.

David expresses the truth that when God sent Nathan to confront David with his sin, God's judgment was true and right and that God's judgment is always true and right, even though David was being a hypocrite. Even though what David did was horribly wrong, when he is confronted with the truth he readily admitted God is always right in His ways and humbles himself before God.

Paul taps into this sentiment to demonstrate that if Jews do not obey God it in no way discredits the judgment of God or the truth of God. David was king of the Jews, and when he sinned, David acknowledged God's righteousness in judging him.

In answer to the question whether the unbelief of the Jews cancels out God's faithfulness (Romans 3:4). Paul exclaims, May it never be!

Paul then exclaims: Rather, let God be found true, though every man be found a liar (v 4). God is always true, even when men who sit in seats of authority stray from God's ways. The fact that these competing Jewish "authorities" claim to represent God when they are actually rebelling against Him is just like David sinning with Bathsheba. The problem is not God, but the "authorities" in rebellion against the truth of God.