Jews in Paul’s time honored Abraham as the founder of Israel. Some Jewish writings even claim that Abraham never sinned (Prayer of Manasseh 8; Jubilees 23:10). Other writings stress his obedience and connect his relationship with God to keeping the law of Moses (1 Maccabees 2:52; Sirach 44:19–20).
Paul argues differently. He shows that Abraham’s faith, not his obedience to the law, is what put him in a right relationship with God. Because Abraham is the founder of God’s people, his example shows that being made right with God by faith stands at the center of God’s plan.