Both E.P. Sanders and H. Raisaner criticized the Apostle Paul saying that he misrepresented Second Temple (esp. Palestinian)Judaism (STJ) when he depicted it as a merit-based, legalistic religion. It is argued that STJ was a religion of “covenantal nomism”. This is to say that the Jews did not see works as means of earning God’s favor since God had already elected Israel. Rather, it was by works that one showed that one was in the covenant or one maintained right-standing in the covenant. The Jews obeyed the law because of election.
J.D.G. Dunn, N.T. Wright, M. Hooker and others have previously argued that Sanders did not give Paul a fair hearing. These scholars have suggested that the traditional Reformed (esp. Lutheran) reading of Paul was incorrect and that we must reinterpret terminology such as “the works of the law”, “the righteousness of God”, “faith in/faithfulness of Jesus Christ” and so forth. This is to say that Sanders is correct in his assessment of STJ, but not Paul.
Douglas Moo offers yet another possibility. He argues along with M. Seifrid, T. Schreiner, P. O’Brien, S. Gathercole, and others that STJ is much more diverse that Sanders allowed. Therefore, it is possible that Paul was in fact challenging some sort of “legalistic” or “merit-based” Judaism. Paul was not challenging STJ as a whole (because it was not uniform) but rather a particular element of STJ that was represented by his opponents. Even if we cannot find STJ literature that sounds exactly like the opponents of Paul it is suggested by Moo that,
Even if the position of Paul’s opponents could not be traced to any Jewish view discernible in the literature, it would still be preferable to admit our ignorance of much of first century theology and let them remain unidentified than accuse Paul of misrepresentations or force the texts to say something that they do not appear to be saying (Moo, Douglas. “Paul and the Law in the Last Ten Years.” Scot. Journ. of Theol. 40: 287-307.).
Of course, there are some scholars who believe that there is as much in STJ literature to suggest merit-based religion as there is “covenantal nomism”. But even if there wasn’t one should assume that Paul knew what he was talking about and that he knew what he was criticizing. Especially since for all the STJ literature we have we do not have enough to know all the aspects involved.