It is often presented by certain individuals that a universal agreement exists in certain debates. This may be possible, but often it is an attempt to be intellectually lazy and maybe even deceptive. In a discussion about Election in the New Testament an individual proclaimed that the Jews had a uniform concept of Election that is very alien to that of Protestant and Reformed thought. That the Pharisees, Essenes, and Sadducees all agreed on the issue of Election.

Fundamental to any study of the history of Judaism in Late Antiquity is the question of how to understand the diversity of the approaches and manifestations that existed at this time. The history of Judaism illustrates in the detail both development over time, the historical factor, and variation even at the same time among different group of Jews, each propounding its own answers to fundamental questions about God, man, and the world.

Two views of the subject immediately present themselves. The first sees each approach to Judaism as independent and self-contained, systematically presenting a fully developed set of answers to the questions at hand. This view effectively isolates each “Judaism” from the others, not only from those that existed at the same time, but also from those that came before and after. Alternatively, one can see the various approaches to Judaism as standing in a dynamic and interactive relationship to one another. In this case, each approach must be studied alongside those in the same period with which it competed, and also in relation to those which preceded and followed it. In this second method, one observes the constantly reciprocal influences between approaches, but also recognizes what each period and approach bequeathed to that which came after.
In this second method that underlies this book. Accordingly, “Judaism” is understood here as a wide designation taking in a variety of ideologies and approaches that coexist with influence one another. Rather than subdividing and compartmentalizing the phenomenon we call Judaism, we prefer to understand the complex historical processes which led the whole, composite and dynamic as it was, to develop in the directions that it did.
The difficulty of finding adequate terminology for the various approaches to Judaism prevalent in the Second Temple times has had some effect on our presentation. In religious studies, it is usual to distinguish a “sect” from the dominant or mainstream “church.” Yet in the study of Judaism in the Second Temple period, the term “sect” is customarily used to describe all approaches to Judaism without implying that any of them was dominant. It is the usage that “sect” appears in this work. Only after Judaism converged around the “mainstream” of tannaitic Judaism, a process that took centuries, can the term “sect” be used to describe those who diverged from its dominant or authoritative form.

Schiffman, Lawrence H.. From Text To Tradition: A History Of Second Temple and Rabbinic Judaism (pg. 4-5)