In Romans 3:21-26, Paul shared that justification by faith alone is received by us freely by God’s grace alone, accomplished entirely on account of the redemption which is in Jesus Christ, as God set Jesus forth as a propitiation, God was vindicated: just and a justified, and worthy of our worship! In Romans 3:27-31, Paul follows the world’s greatest paragraph by demonstrating how our theology matters to how we consider ourselves, others, and God and his law.
After articulating his gospel centering on righteousness from God through justification by faith in Jesus Christ alone, Paul points us to God’s justifying Abraham (Genesis 15:6) as proof that justification is by faith alone (Romans 4:1-3), and David’s testimony in Psalm 32 (Romans 4:7-8).
Paul clarifies that God justifies the ungodly through the costly free gift counted to the sinner who believes, not due to any works we do. Only those who are justified in this manner can live happy/blessed.