The book is divided into four chapters--on the significance of the first century, on Palestinian Judaism, on Hellenistic Judaism, and on Christianity. Of course, the first century is very significant, for out of it springs Rabbinic Judaism and Christianity. Knowing this century is in essence to know the origins of these two faiths. Too bad it is so hard to know much about the century.
The next chapter goes into this origin of Rabbinic Judaism, wherein the author has difficulty finding where the moment that Pharisaical Judaism transition into Rabbinic is (if indeed this concept is even correct). As for what we do know: Jews read scriptures at service, though the set Parsha calendar may or may not have existed at that time. The sermon, as we know, may have come before the first century or maybe later--it is hard to know how a short explanation of a given scripture transformed into a full-on discourse on the subject or when it exactly happened. Were there two Sanhedrin, one political and one religious? And did they (or one of them) have authority over life and death, and if so, why did Rome have to be involved when putting Jesus to death? The major issue throughout is that our major sources are religious (Rabbinic writings) or historical (Josephus), but there is not historical religious source, so we have to glean what we can from each.
The chapter of Hellenistic Judaism does a lot of comparing of Philo's views to those of Paul. And the chapter of Christianity focuses on how, in the author's view, most of the writing in the New Testament tells us more about the time in which the books were written than about the first century. In the author's view, most of the New Testament was written much later, some as late as the second century. Here, the author's view, corresponding to mainstream Protestant beliefs, that Paul created a radical break with the Jewish law, colors most of the author's views. Since the author is Jewish I suppose I can't be surprised that he looks on the New Testament from a largely secular perspective and, thus, is prone to dismissing much of the more typically religious view of the writing of the works. But I came to this work hoping to find out more about the Judaism of the time, and the fact that the author feels there are so many uncertainties that he can't make too many claims rather disheartened me to the extent that by the time I came to this final chapter, his views left me rather unimpressed.