This work offers a fresh reading of Paul's appropriation of Abraham in Gal 3:6–29 against the background of Jewish data, especially drawn from the writings of Philo of Alexandria. Philo's negotiation on Abraham as the model proselyte and the founder of the Jewish nation based on his trust in God's promise relative to the Law of Moses provides a Jewish context for a corresponding debate reflected in Galatians, and suggests that there were Jewish antecedents that came close to Paul's reasoning in his own time. This volume incorporates a number of new arguments in the context of scholarly discussion of both Galatian 3 and some of the Philonic texts, and demonstrates how the works of Philo can be applied responsibly in New Testament scholarship.