The Gospels
We can also prove the point by looking out how the Gospels deal with the issue of Jewish unbelief. Never do the Gospels make a distinction between the ceremonial laws and the rest of the Mosaic laws. For example, in Matthew 12:8-14, the Pharisees are questioning whether it is lawful to heal on the Sabbath. Sabbath observance was the Third Commandment of the Decalogue. Jesus answers them by pointing out that David ate the Showbread, which was only lawful for the priests; and by pointing out that any of them would save his sheep if it fell into a ditch on the Sabbath. Having answered their challenge, Jesus then heals the man who was presented to him. The Pharisees then conspire to murder Jesus.
The point of the story is to show us that the Pharisees think it is unlawful to heal on the Sabbath, but perfectly lawful to plot the murder of Jesus! This shows that their problem was inner corruption. They were lovers of law, but haters of God and man. THAT is their problem, not merely "being Jewish." There is no Jew/Gentile controversy in Matthew 12.
And this is precisely why Paul, in Romans 11:1-10, says that the Jewish problem of "works versus grace" stemmed all the way back to the time of Elijah in the eighth century BC, not merely when the Gentiles come on the scene in the first century AD.
Now, some might object that any self-respecting Rabbi would be forced to agree. Faith is the ground on which circumcision and all of the "works of the law" were based. A man who was physically circumsized and went through the motions of keeping the Law was no real Jew. The Rabbis themselves acknowledged that one should keep the commandments out of LOVE for God. Any other motive was unacceptable.
But, as noted previously, the problem was that "self-respecting" Rabbis were few and far between in the century leading up to Jesus' coming. If the "Pharisees, Sadducees, scribes and lawyers" described by Jesus in the NT are any indication of the theological sentiment residing in the Rabbis, then there really wasn't a large contingent of Jewish leaders who would have prescribed to the above altruism.
This is an important point, since the Dunn, et al, hermeneutic attempt to make religious groups such as the Pharisees into a more or less respectful theological concern at the time of Jesus, rather than the scoundrels Jesus identifies them to be.
The only ones who aspire to the altruism described above (at least according to the NT) are people like Mary and Joseph, John the Baptist, Elizabeth and Zacharias (Luke 1:6), Nicodemus, and a few others. All the rest, by and large, were in unbelief, that is, they didn't have "faith" and did not understand the true purpose of the Law.
According to Paul, there was only a "remnant" who believed, and a "remnant" is a small portion of the whole. His example in Romans 11 is that out of a nation of a million+ people, there were only 7000 who weren't in unbelief. So, if they were in unbelief, what is the natural mentality they are going to adopt? Its not going to be faith, its going to be what unbelief produces – a reliance on works.
The Gentiles and Works
We can also prove the point by showing that the "works of the law" was not a problem only among the Jews, but the Gentiles themselves were tempted to think that God was in debt to pay them with salvation. To combat this, Paul continues the "grace versus works" theme throughout his writings.
For example, in 1 Corinthians 4:7 (the very verse St. Augustine used to show the true nature of Justification), Paul says:
"For who regards you as superior? What do you have that you did not receive? And if you did receive it, why do you boast as if you had not received it?"
Notice the same accusation against the Corinthians concerning their "boasting" that Paul used against the Jews in Romans 2-4 when he was speaking about their self-aggrandizing behavior. In four passages, Romans 2:17; 2:23; 3:27 and 4:2 Paul uses the word "boasting." He does so because the Jews were boasting that because they merely possessed the Law of Moses that God owed them salvation. Now, in the Corinthian letter, we see that the Gentiles began to think the same way about the Christian religion, thinking that somehow, because of their own efforts, they earned what they had received. The problems for the Corinthians in this regard are enormous. Almost every chapter of the epistle is an indictment against their boastful pride.
"Works of the Law" - Page 12