One of the best essays I’ve ever read on Romans is Andrew Lincoln, “From Wrath to Justification: Tradition, Gospel, and Audience in the Theology of Romans 1:18–4:25,” in Pauline Theology: Volume III Romans, eds. D.M. Hay and E.E. Johnson (Minneapolis: Fortress, 1995), 130-59. I esp. like his conclusion:
This essay has traced three main coordinates in the theology of Rom 1:18–4:25—tradition, which provides most of the symbol system within which the argument takes place; gospel, which supplies the convictions by which the symbols are realigned and reshaped; the audience, whose needs influence the argument but are interpreted in light of the gospel. In the letter as a whole it is because Paul conceives of the gospel as for all, both Jews and Gentiles—but for the Jew first—that he can be even-handed in his rebuking of the pride on both sides. In this first part of the letter it is because of his particular conception of the gospel, deriving from his call to Gentile mission, that he pulls no punches in dealing with the obstacles in Jewish Christian thinking to their acceptance of his gospel, asks for a radical reassessment of some of their cherished views, and even depicts Abraham as one who has seen the full implications of justification by faith. Thus, in regards to Paul’s theology in Rom 1:18–4:25, it can be said that tradition, gospel and audience abide, these three; and the greatest of these is gospel. (p. 159).