In Christ There Is Jew and Greek
Steven Carr asks a good question: "Did Paul think Gentiles were not as good as Jews?". This was my reply:
"In some ways Paul portrays Gentiles as better than Jews in Galatians: Jews are under a curse (Gal 3:10-12), while law-free Gentiles are the real descendants of Abraham (Gal 3:6-9,13-14). But at the same time he's calling for an abolition of distinction (in view of the apocalypse): 'in Christ there is neither Jew nor Greek' (Gal 3:27-28).Paul was no more an egalitarian than Jesus, and by the time of Romans he had even given up on the apocalyptic formula of Gal 3:27-28 (cf. I Cor 12:13). The reason is simple: Gal 3:27-28 was offensive, impractical, and doomed to fail in the ancient Mediterranean, where different ethnic groups, genders, and social classes could get along only by preserving their identities. Attempts to eliminate distinctions in honor-shame societies only encouraged groups to re-assert their identities in aggressive ways. That's why there is Jew and Greek in Christ, after all.
"He portrays Jews as the better group in Romans (Rom 3:2, 9:4-5, 11:1-32). But for the most part we should say he thought Gentiles were as bad as Jews, though in different ways which preserve ethnic distinctions between the two groups. Gentiles are under the domain of sin without the Torah (1:18-2:5), Jews under its power with the Torah (2:17-3:20). In Christ there is Jew and Greek: through baptism Gentiles are liberated from the power of sin which ruled them as immoral pagans (6:15-23), while Jews are liberated from the power of sin which ruled them through the law (7:1-6). Paul respects ethnic identity in Romans and keeps distinctions intact, contrary to Galatians.
"The fact that Paul treats Gentiles as the better race (even while trying to abolish distinctions between the two) in Galatians, then Jews as the better race (even while insisting that both are in messy situations without Christ) in Romans, tells against him thinking like an egalitarian. In his ancient mind, someone always had to be better than the other."
Rom 6:1-7:6 was the winning formula, not Gal 3:27-28. Likewise, it was better for Paul to insist that his own race was superior to the Gentiles, rather than imply the opposite in trying to eliminate distinctions.
UPDATE: See Mark Goodacre's comments, with which I agree, as he notes that "for 'egalitarian' in scholarship on the New Testament, we should substitute 'eschatological'."