Studying modern scholarship on Second Temple Judaism is kind of a brain drain. From what I can tell, there is a strong consensus around Ed Sanders’s portrayal of Judaism, based on Jewish sources ancient and modern, as a religion based on a gracious covenant given by God. And there is also the counter-element, including many (most?) Evangelical scholars, who believe that there must have at least been a significant works-righteousness element in Judaism for Paul to be arguing against; this is imperative to maintain a Lutheran (classical Protestant) reading of Paul, the messenger of grace, against Judaism, the religion of empty works.
Strangely enough, though, I detect an element in Christianity that is a bit too keen on the idea of perfection. We want to read perfection into everything. We want to perceive the Bible as a perfect book (and it is), because it’s from God, so it must have no errors and it must have all the answers, notwithstanding the fact that our thousands of manuscripts do indeed have small differences due to textual transmission, and there are many questions the Bible does not propose to answer, or that it answers in a way that is vague or open to interpretation.
The results of his research he has compiled in an easy-to-read, affordable, and highly recommended hardback called 
