There is no word for “Judaism” in the Hebrew Bible, nor in the premodern Hebrew language itself. The Greek term Ioudaismos, from which the word “Judaism” derives, was coined at the close of the biblical period (2Macc 6:6, 2Macc 9:17) and was used, prior to the modern era, almost exclusively by Christian writers as a term to describe a counterpart religion to Christianity. In recent centuries, Judaism has become the common designation for the sacred traditions and ritual practices of Jews—and, by association, if somewhat anachronistically, of the Israelite peoples (also called “Hebrews”) with whom the bulk of the Hebrew Bible is concerned.
The biblical word for “Jews” in Hebrew, yehudim (“Judahites”), begins to appear only in later books of the Hebrew Bible, most particularly in Ezra, Nehemiah, Esther, and Daniel, all of which were composed during the Second Temple period. “Jews” appear far more often in the much-shorter New Testament than they do in the entire Hebrew Bible/Old Testament.
The “emergence of Judaism,” then, presents complex and contentious issues. Insofar as the word yehudim comes into currency only after the destruction of both the northern kingdom of Israel and the southern kingdom of Judah and the subsequent Babylonian exile, “Jews” as a collective entity embracing distinctive sacred traditions and ritual practices must be regarded as a postexilic phenomenon. Judaism, as the term is commonly used, would then refer to a culture that emerged out of the destruction and displacement of the ancient Israelite kingdoms and their monarchies.
Scholars pinpoint a variety of time periods and sociopolitical forces or events in accounting for the emergence of Judaism. Time periods proposed range from the Babylonian and Persian periods (sixth to fourth centuries B.C.E.) to the Hellenistic period (fourth century B.C.E. forward), to the earliest centuries of Christianity with its gradual formulation of the concept of “religions” by which to categorize different peoples, including Jews. Scholars who locate the emergence of Judaism within the Babylonian and Persian Empires highlight the experience of Diaspora and subjection as fundamental to its shaping, whereas those who assert a Hellenistic context emphasize the encounter with specifically Greek (and, later, Roman) concepts and institutions as key to its formation. In any case, virtually all forms of Judaism that survive in our current era derive from the rabbinic movement, a school of Jewish thought and practice that developed alongside early Christianity under Roman, Byzantine, and Sasanian rule.
Perhaps the most salient feature of emergent Judaism is the inherent tension between ancient Jews’ widely shared traditions and their widely divergent understandings and interpretations of these. For example, although “Torah” became a key concept throughout emergent Judaism, not only did Jews ascribe diverse meanings to the words of their Scriptures, but different groups understood Torah itself in various ways: as a closed or an open canon; as an embodied practice or a collection of philosophical allegories, folklore, or even magical formulae; as a living constitution or a dead law, and so on. This tension has led some prominent scholars to speak of ancient Judaisms, in the plural, as a way to signify the relative absence of normative doctrine or creed and a notable diversity of popular, elite, sectarian, and local Jewish practices.