First, regarding first-century Judaism, the New Perspective on Paul claims that the Judaism of Paul's day was not really a religion of self-righteousness where salvation depended on human works and human merit. So we've misunderstood Paul because we have misunderstood what he was up against. The Pharisees weren't legalists after all, it turns out. But they have been misunderstood by biased exegetes who erred because they superimposed Augustine's conflict with Pelagius and Luther's conflict with Roman Catholicism onto their reading of Paul's conflict with the Judaizers.
Instead, according to the New Perspective, there was a strong emphasis on divine grace in the Judaism of Paul's time, and the Pharisees were not really guilty of teaching salvation by human merit. This is the one basic point upon which Sanders, Dunn, and Wright are all in full agreement. They base that claim primarily on their study of extrabiblical rabbinical sources, and they treat the matter as if it were settled in the world of New Testament scholarship—even though it seems to me that there are still plenty of weighty New Testament scholars who would strongly disagree with them. But that's the starting point of their view: first-century Judaism was not legalistic after all. For centuries, Christians have simply misunderstood what the Pharisees taught.
Second, regarding the apostle Paul, the New Perspectivists are very keen to absolve Paul from the charge of anti-semitism—and therefore they deny that he had any serious or significant theological disagreement with the Jewish leaders of his time. Obviously, if the religion of the Pharisees was a religion of grace and not human merit, then Paul would have had no fundamental disagreement with them on the doctrine of salvation.
But Paul's real controversy with the Jewish leaders, we are told, had to do with the way they treated Gentiles. His conflict with the Judaizers and the Pharisees had to do more with racial and cultural differences than with any kind of soteriological debate. They tell us that Paul's great concern actually was for racial harmony and diversity in the covenant community. So the only significant complaint Paul had with the Pharisees and the Judaizers was their racial and cultural exclusivity.
Third, regarding the gospel, the New Perspective on Paul claims that the gospel is a message about the Lordship of Christ, period. It is the declaration that Christ, through His death and resurrection, has been shown by God to be Lord of creation and king of the cosmos. We would agree that this truth is an essential feature of the New Testament gospel, of course. But we would not agree with advocates of the New Perspective when they say the gospel is therefore not really a message about personal and individual redemption from the guilt and condemnation of sin.
