Fully cognizant of the scope of the Abraham story, Paul bluntly states “For if Abraham was declared righteous by the works of the law,” or if Abraham was justified (placed under the auspices of God’s covenant) by the act of circumcision (encapsulating covenant markers with “circumcision”), “he has something to boast about” (4:2a). So yes, if Abraham has been declared to be in right standing with God because of his circumcision, then he could point to that very circumcision as the source of his right standing. This, however, would be to get the cart before the horse so to speak, so Paul adds “but not before God” (4:2b). He may be able to convince the people around him that God found him righteous (in right covenant standing), and therefore had Abraham undergo circumcision as a mark of that prior right standing, but he certainly could not put that over on God.
So Paul, seeking to elevate faith, with faith being belief in Jesus as Messiah, as the means by which one gains righteousness, inquires as to what the Scripture says (4:3a) and answers his own question with “Abraham believed God, and it was credited to him as righteousness” (4:3b). It is not a matter of works versus faith, but it is a matter of order. For Abraham, it was belief in the faithful, covenant God that was primary, and which eventually led to the mark of the covenant that he would come to bear. This is what Paul believes God is now doing in relation to Jesus and the extension of the covenant to Gentiles.
The covenant marker of circumcision, that began with Abraham, is not the means of entrance upon the covenant, but is only the mark of trust in the God of the covenant. For Gentiles, justification comes from belief in the God of the covenant, which entails a belief in Jesus as Lord of all, and the mark of circumcision will be that of the heart rather than of the flesh. In this way then, Paul has identified Abraham with the Gentiles, placing him on par with the Gentiles, and so elevating the Gentiles to the status of Abraham. This is a bold, rhetorical move.
Using this very obvious and undeniable example of Abraham and his “order of salvation” (belief, assumption under covenant, then covenant marker), Paul writes “Now to the one who works, his pay is not credited due to grace but due to obligation” (4:4). We here must resist the tendency to fall back into old habits of thought that equates “works” with “attempting to earn righteousness and therefore a trip to heaven upon death through doing good deeds.” Though Paul is using the analogy of actual work and actual payment for actual work, the larger analogy, which is that of works of the law as covenant marker and means of justification, versus belief in Jesus as covenant marker and means of justification, holds sway. Continuing then, Paul adds “But to the one who does not work, but believes in the one who declares the ungodly righteous, his faith is credited as righteousness” (4:5). This is precisely the example that both Jew and Gentile have in Abraham.
Abraham is introduced into the story of God’s covenant people (that begins with Adam) at the close of the eleventh chapter of Genesis. There, we hear about Abraham’s (Abram’s) father, his brothers, his nephew, his wife, and his sister-in-law, but we do not have any biographical information about Abraham that would allow us to make a determination as to his nature as a person and whether or not he could be considered to be “righteous” in a moral sense, or “saved” in the popular sense, and thus worthy of his coming communication with the Creator God of the universe. It is immediately after learning about nothing more than Abraham’s immediate family that the story of God’s covenant people proceeds to the record of God bringing Abraham into covenant with him, and the making of promises concerning him and his descendants (that will be reiterated, expanded upon, and eventually passed along to son, grandson, and to succeeding generations).
God simply comes to Abraham. There is no evidence of pre-Torah or pre-Torah-based-tradition activity on Abraham’s part that could be construed as justification-indicating covenant markers. As far as we know, Abraham is as ungodly as the rest of humanity. If we are hearing or reading Genesis for the first time, and have just come across this information about Abraham’s family that follows the story of the Tower of Babel, the division of the nations, and the genealogy of Shem, we would not have any basis to expect that, following the record of Abraham’s father’s death, that the God of creation is going to speak to this character named Abraham (Abram) for the purpose of creating an eternal covenant by which He is eventually going to re-unite the peoples of the world (that had just been divided into distinct language groups and scattered to the four winds). In all reality, God’s selection of Abraham, and His speaking to Abraham in the way that is recorded here in Genesis, should be of considerable and paradoxical surprise to a member of Israel, especially considering that the God of Israel speaks and makes promises to one who is not circumcised and who does not adhere to the covenantal practices that indicate that one is in a position of right standing and thus reasonably able to expect to experience such an encounter. Nevertheless, this is precisely what happened, and it is precisely that by which the Abraham tale, so crucial to the collective consciousness of Israel, is composed.