The word Judaism first meant something closer to Judaeanness than to a religion
When the Greek term behind Judaism first appeared, in the book of 2 Maccabees in the 2nd century BCE, it named a whole way of being Judaean, set against those who adopted Greek customs. Only later did it narrow to mean a religion, one of the earliest monotheistic faiths and a root of Christianity and Islam.
The Greek word Ioudaismos grew from a verb meaning to side with or imitate the Judeans, and ultimately from Yehudah, the Hebrew name of Judah, son of Jacob. In 2 Maccabees it stood opposite Hellenismos, submission to Greek cultural norms, and that clash fed the Maccabean Revolt. Shaye J. D. Cohen argues the early term covered every trait that made Judeans who they were; Daniel R. Schwartz counters that it already pointed to religion. In English, the word shows up in a 1516 chronicle by Robert Fabyan.
Religious Jews see their practice as keeping the covenant with God given through Moses. The core scripture is the Tanakh, an acronym for its three parts: Torah or Teaching, the Prophets and the Writings. Alongside it stands the Oral Torah. Rabbinic tradition holds it was first passed down unwritten, until mounting persecution led Judah ha-Nasi to compile the Mishnah around 200 CE. Commentaries built on it over three more centuries formed the Talmud, produced in two versions, one in Palestine and one in Babylonia.
The biblical story runs from Abraham, given circumcision as the sign of the covenant, through slavery in Egypt, the Exodus and the laws at Sinai. History brought repeated upheaval: Babylon destroyed the First Temple, launching the first diaspora, and Rome later razed the Second Temple during the war of 66 to 73 CE. After the Bar Kokhba revolt, Rome banned Torah study; yet by 200 CE Jews held Roman citizenship and their faith was a legally recognised religion.
No single person or body holds final authority; that rests with the texts and the scholars who interpret them. Orthodox Judaism treats Torah and Jewish law as divine and unchangeable, Conservative Judaism reads the law more flexibly, and Reform Judaism often views it as general guidance. Estimates for 2025 put the number of Jews worldwide at about 14.8 million, with observance ranging from strict to none.
Source: Judaism
