Kofer

Heresy in Orthodox Judaism (Hebrew: כְּפִירָה‎ kefira) is not principally defined, but is usually understood as a departure from the traditional understanding of the Jewish concepts of the uniqueness of God or of the Torah as being divinely inspired. In contemporary society, Orthodox Judaism widely holds that most Jews distanced from religious identification and practice are considered to be in the Talmudic status of Tinok shenishba, brought up without sufficient knowledge of Judaism to be expected to follow it, and instead should be welcomed to discover Jewish thought and observance as much as possible.

The Greek term ἁίρεσις originally denoted "division," "sect," "religious" or "philosophical party," and is applied by Josephus to the three Jewish sects: Sadducees, Pharisees, and Essenes. The specific rabbinical term for heresies, or religious divisions due to an illegitimate spirit, is מינים (minim) (lit. "kinds [of belief]"; the singular מין (min) (literally, "a kind") for heretic or Gnostic is coined idiomatically, like goy and `Am ha-aretz). An alternative term, אפיקורוס (Apiqoros/Apikoros), which may have a different status, and is often used for apostates who turned towards agnosticism or atheism, is derived from Epicurus and the philosophy of Epicureanism.

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