“For by the works of the law no human being will be justified in His sight, since through the law comes knowledge of sin” (v20). Knowing the rules and attempting to follow them isn’t enough to save Jews or Gentiles, since we inevitably fail. “For there is no distinction” (v22). All humans everywhere are the same; we all have sinned, and forgiveness and restoration is made possible only “through faith in Jesus Christ for all who believe” (v22).
“Boasting” (v27) in our own goodness is impossible when we realize how far we are from God’s holiness. But through Jesus, we are “justified by his grace as a gift” (v24).