I started Francis Watson's Paul, Judaism and the Gentiles: A Sociological Approach. Watson's argument so far appears to be that Paul was once a Christian missionary to the Jewish people, but he turned to the Gentiles after his lack of success among the Jews, and he did not require Gentiles to be circumcised or to observe the Jewish days and dietary regulations because that would make their entrance into the Christian community easier, considering that Gentile society looked down on these customs. But, because Judaism viewed these customs as markers of who was in the people of God, Paul's stance that Gentiles did not have to observe them to be part of God's people separated the church from the synagogue, as did Paul's insistence that many Jews who did observe them were outside of God's people due to their refusal to believe in Christ.
Watson's approach is characteristic of the New Perspective in that it states that Paul arrived at his view on the Gentiles and the law in response to the entrance of Gentiles into the church, not as a result of his guilt over his failure as a Jew to live up to the law's demands, or his belief that he in his Pharisaic days was self-righteous about his observance of the law. Watson describes the Lutheran depiction of Paul in Chapter 1 of his book, primarily in an attempt to knock it down later on. I did, however, appreciate one of Watson's quotations of Martin Luther. In his comment on Galatians 3:10, in his 1535 lectures on Galatians, Luther states the following:
"To want to be justified by works of the Law is to deny the righteousness of faith. On this basis, when those who are self-righteous keep the Law, they deny the righteousness of faith and sin against the First, Second, and Third commandments, and against the entire Law, because God commands that he be worshipped by believing and fearing Him. But they, on the contrary, make their works into righteousness, without faith and against faith. Therefore in their very keeping of the Law they act in a manner that is contrary to the Law, and they sin most seriously and grievously...The righteousness of the Law which they think they are producing is in fact nothing but idolatry and blasphemy against God."
This goes back to Tim Keller's The Prodigal God, which I blogged through in October (or, more accurately, I blogged about that and my church's study of it). When I do good things, am I worshiping myself or trying to manipulate God, or am I loving God----God's goodness, God's kindness, God's love for justice, etc.? I don't think that it's wrong for me to congratulate myself when I do something good, for, after all, God in the Bible commends righteous behavior. I also understand a desire people may have to manipulate God for personal security, and that is biblical, in a sense, since the Bible has systems of reward and punishment (but things don't necessarily work so neatly in real life). But I can also see Luther's point that it's good for me to set my sights on someone higher than myself, to place my good deeds within the larger context of God's love. Luther, of course, most likely believed that Judaism did not do so, that it was a religion of self-righteousness and boasting. Granted, Judaism does emphasize the value of mitzvot, and it affirms that there is such a thing as divine reward and punishment. But love for God, and an acknowledgement of God's goodness, play a significant role in Jewish observance of the commandments.