Abraham—the Father of All Who Believe
In all the history of the Jewish people, there was none counted greater than Abraham. In John 8 the Jews continually insist that Abraham is their father, a claim in which they took great pride. And indeed, he was their father, literally, their progenitor. I am told that in some of their apocryphal and pseudepigraphal works, Abraham is described as “perfect in all his deeds” and that “no one has been found like him in glory” (Moo, NICNT, 278). For the Jews, he was ever an exemplar of the faith, the pattern of obedience which every Jew should follow.
But Paul sees Abraham in a slightly different light than his Jewish brethren. Whereas the Jews of Paul’s day saw Abraham as their father to whom they had exclusive rights, Paul sees Abraham as the father of all who believe—Jew and Gentile. And how does Paul do this? He does this by showing that Abraham was reckoned as righteous before God, not by works, but by faith. Paul argues that to the one who works, his wages are not awarded him as a gift but as his due; after all, the laborer is worthy of his hire (1 Timothy 5:18). But just as he used Habakkuk 2:4 (“The righteous shall live by faith,” in 1:17), Paul now quotes Genesis 15:6 which becomes yet another key passage for him when arguing that salvation by grace through faith for all who believe is the doctrine taught in the Law and the Prophets, whose words Jesus came to fulfill in his life, passion, and resurrection. God had promised Abraham that he would have a son, even at his advanced age, and since “Abraham believed God,” Paul quotes Genesis 15:6, “it was counted to him as righteousness.” Thus, from Genesis 15:6, Paul deduces two things: 1) Abraham was counted righteous before God on the basis of his faith, not his works, on the basis that he believed God’s promise, not on the basis of anything he did; and, 2) that Abraham was so counted as righteous before he was circumcised, which command God did not give until later (Genesis 17). Paul then concludes that Abraham is then the father all who trust God for salvation apart from works (per #1), and God’s fatherhood includes believing Gentiles though they be uncircumcised in the flesh (per #2).
I know, it all sounds very theological. Paul just wants his Jewish brethren to understand that God has broken down the wall between all who believe on the basis of faith (Ephesians 2:14). And what is more wonderful to hear than, “Blessed are those whose lawless deeds are forgiven, and whose sins are covered; blessed is the man against whom the Lord will not count his sin” (Psalm 32:1-2). To be counted righteous by God is to be forgiven of sin.