In Galatians 2:15-21, the Apostle Paul outlined a clear argument explaining why sinners can only be justified before God by faith in Christ and not following the Law or doing good works. This is one of the classical passages in the debate about the “new perspective” on Paul and the age old discussion about what a person must do to be saved from God’s wrath against sin.
Following Paul’s rebuke of Peter, the passage makes it clear that 1.) no one will be justified by works, 2.) in trying to justify ourselves, we discover our sinfulness, 3.) believers are nailed to the cross with Christ and die to the law, 4.) Christians live in the flesh by faith in Christ, and 5.) works nullify grace and Christ’s sacrifice on the cross.
The new perspective on Paul stems from research by E.P. Sanders. And the crux of the debate revolves around what exactly did Jews believe about salvation and works during the time of Paul. This reflection helps modern readers better understand Paul’s chief concern with the Judaizers. Sanders maintained that the Jews were not looking to works to save them as many Christian scholars had suggested.
I partially agree with Sanders that not all Jews held this belief while some obviously did or at least Paul saw it as a threat to Gentiles converts. I believe all people are somewhat hardwired from the beginning to default to work’s based righteousness even if we start out claiming “Grace, Grace.”
It is not as much as a Jew/Gentile thing as a human condition. Thus, it is impossible to concretely say one way or the other what Jews believed during Paul’s day, and more than likely, there was a wide variety of experiences and opinions on the subject.