Sources: Maimonides, Commentary on the Mishnah, Introduction to Chapter Chelek (Sanhedrin 10) ~1168 AD; Mishneh Torah, Laws of Repentance 3:6–8; the Ani Ma’amin and Yigdal liturgical formulations.

Maimonides’ Thirteen Principles of Faith are the closest thing to a Jewish creed — a list of the irreducible theological commitments without which, Maimonides argues, a Jew has no share in the World to Come. They are: (1) God exists; (2) God is one and unique; (3) God is incorporeal; (4) God is eternal; (5) God alone is to be worshipped; (6) Prophecy exists; (7) Moses’s prophecy is supreme; (8) The Torah is divine; (9) The Torah is immutable; (10) God knows human actions; (11) God rewards and punishes; (12) The Messiah will come; (13) Resurrection of the dead. The Principles generated immediate controversy. Critics noted that Maimonides derived them from Aristotelian philosophy as much as from scripture — God’s incorporeality (Principle 3) is not explicitly stated in the Torah and was fiercely contested. Nachmanides objected that some principles appear more central than others; Abravanel argued that a hierarchical creed was foreign to Judaism’s character. Hasdai Crescas (Or Adonai, ~1410 AD) proposed alternative fundamental principles. The theological significance: Maimonides is the first to define Jewish heresy precisely — not as moral failure but as incorrect belief about God’s nature. This intellectualist move (right belief defines membership) is more characteristic of Christian theology than rabbinic Judaism’s traditional action-centered definition of covenant membership. The Yigdal hymn and Ani Ma’amin formula (both based on the 13 Principles) became standard synagogue liturgy, embedding Maimonidean theology into daily Jewish worship across all communities.