The Gospel: God’s Power and the Righteousness Revealed by Faith
Paul states the letter’s program: he is not ashamed of the gospel because it is God’s power for salvation to everyone who believes, to the Jew first and also to the Greek. In it God’s righteousness is revealed “from faith to faith.”
Paul then reaches backward to Habakkuk 2:4: “The just shall live by faith.” Habakkuk originally spoke into a crisis of judgment and faithful endurance; Paul makes its faith-language programmatic for the saving righteousness revealed in the gospel.