Judaism

Judaism (Hebrew: יַהֲדוּת‎, romanized: Yahăḏūṯ) is an Abrahamic, monotheistic, ethnic religion that comprises the collective spiritual, cultural, and legal traditions of the Jewish people. Religious Jews regard Judaism as their means of observing the Mosaic covenant, which they believe was established between God and the Jewish people. The religion is considered one of the earliest monotheistic religions.

Jewish religious doctrine encompasses a wide body of texts, practices, theological positions, and forms of organization. Among Judaism's core texts is the Torah—the first five books of the Hebrew Bible—and a collection of ancient Hebrew scriptures. The Tanakh, known in English as the Hebrew Bible, has the same books as Protestant Christianity's Old Testament, with some differences in order and content. In addition to the original written scripture, the supplemental Oral Torah is represented by later texts, such as the Midrash and the Talmud. The Hebrew-language word torah can mean "teaching", "law", or "instruction", although "Torah" can also be used as a general term that refers to any Jewish text or teaching that expands or elaborates on the original Five Books of Moses. Representing the core of the Jewish spiritual and religious tradition, the Torah is a term and a set of teachings that are explicitly self-positioned as encompassing at least seventy, and potentially infinite, facets and interpretations. Judaism's texts, traditions, and values strongly influenced later Abrahamic religions, including Christianity and Islam. Hebraism, like Hellenism, played a seminal role in the formation of Western civilization through its impact as a core background element of early Christianity.

Within Judaism, there are a variety of religious movements, most of which emerged from Rabbinic Judaism, which holds that God revealed his laws and commandments to Moses on Mount Sinai in the form of both the Written and Oral Torah. Historically, all or part of this assertion was challenged by various groups, such as the Sadducees and Hellenistic Judaism during the Second Temple period; the Karaites during the early and later medieval period; and among segments of the modern non-Orthodox denominations. Some modern branches of Judaism, such as Humanistic Judaism, may be considered secular or nontheistic. Today, the largest Jewish religious movements are Orthodox Judaism (Haredi and Modern Orthodox), Conservative Judaism, and Reform Judaism. Major sources of difference between these groups are their approaches to halakha (Jewish law), rabbinic authority and tradition, and the significance of the State of Israel. Orthodox Judaism maintains that the Torah and Halakha are explicitly divine in origin, eternal and unalterable, and that they should be strictly followed. Conservative and Reform Judaism are more liberal, with Conservative Judaism generally promoting a more traditionalist interpretation of Judaism's requirements than Reform Judaism. A typical Reform position is that Halakha should be viewed as a set of general guidelines rather than as a set of restrictions and obligations whose observance is required of all Jews. Historically, special courts enforced Halakha; today, these courts still exist but the practice of Judaism is mostly voluntary. Authority on theological and legal matters is not vested in any one person or organization, but in the Jewish sacred texts and the rabbis and scholars who interpret them.

Jews are an ethnoreligious group including those born Jewish, in addition to converts to Judaism. In 2025, the world Jewish population was estimated at 14.8 million, although religious observance varies from strict to nonexistent.

The term Judaism derives from Iudaismus, a Latinized form of the Ancient Greek Ioudaismos (Koine Greek: Ἰουδαϊσμός, from the verb ἰουδαΐζειν 'to side with or imitate the [Judeans]'). Its ultimate source was Hebrew: יהודה, romanized: Yehudah 'Judah' (referring to the Kingdom of Judah), which is also the source of the Hebrew term for Judaism, יַהֲדוּת Yahaḏuṯ. The term Ioudaismos first appears in the Koine Greek book of 2 Maccabees in the 2nd century BCE (specifically 2 Maccabees 2:21, 8:1 and 14:38). In the context of the age and period it meant "seeking or forming part of a cultural entity". It resembled its antonym Hellenismos, a word signifying people's submission to Hellenistic cultural norms. The conflict between Ioudaismos and Hellenismos lay behind the Maccabean Revolt and hence the invention of the term Ioudaismos.

Shaye J. D. Cohen writes in his book The Beginnings of Jewishness:

We are tempted, of course, to translate [Ioudaïsmós] as "Judaism," but this translation is too narrow, because in this first occurrence of the term, Ioudaïsmós has not yet been reduced to the designation of a religion. It means rather "the aggregate of all those characteristics that makes Judaeans Judaean (or Jews Jewish)." Among these characteristics, to be sure, are practices and beliefs that we would today call "religious," but these practices and beliefs are not the sole content of the term. Thus Ioudaïsmós should be translated not as "Judaism" but as Judaeanness.

Daniel R. Schwartz, however, argues that "Judaism", especially in the context of the Book of Maccabees, refers to the religion, as opposed to the culture and politics of the Judean state. He believes it reflected the ideological divide between the Pharisees and Sadducees and, implicitly, anti-Hasmonean and pro-Hasmonean factions in Judean society.