How did the apostle Paul expand the idea of Abraham’s descendants in Galatians?

In his Letter to the Galatians, the Apostle Paul expanded the definition of Abraham’s descendants by shifting the basis of religious identity from ethnicity and ancestry to faith.1

While traditional Jewish thought identified Abraham’s descendants through physical lineage and the covenant sign of circumcision, Paul argued that these requirements were not necessary for Gentiles to be considered part of the people of God. Instead, Paul utilized the story of Abraham—who was "reckoned" as righteous because he believed God—to establish that all individuals, regardless of their background, become descendants of Abraham through faith in Jesus Christ.213

Paul’s argument in Galatians 3:29 explicitly states, "If you belong to Christ, then you are Abraham’s offspring, heirs according to the promise". By redefining the "seed" of Abraham as the Messiah and those united with him, Paul broke down the traditional partitions between Jew and Gentile, asserting that spiritual inclusion is defined by belief rather than adherence to the Torah.13