Part 4 (Galatians 2:15 – 3:9) drills down on the heart of Paul’s argument: the Law diagnoses our sin, but only faith in the crucified and risen Christ cures it. After finishing his face-off with Peter, Paul tells the Galatians that even Torah-keeping Jews like himself and Peter know they’re justified solely by trusting Jesus. If righteousness could come through rule-keeping, the cross was pointless—but it didn’t, so Paul can say, “I no longer live, Christ lives in me.” Turning to the churches, he asks: did you receive the Spirit by doing the Law or by believing the gospel? Remember Abraham—declared righteous simply because he believed God—so anyone, Jew or Gentile, who rests in Christ is blessed along with “the man of faith.” Bottom line: the Law exposes our need; Jesus alone meets it, and faith alone unites us as heirs of God’s promise.