Who founded Judaism?

Abraham

Maimonides describes how Abraham, growing up among idol worshippers, reasoned his way to the one Creator, then began to teach it publicly and gathered thousands of followers (Mishneh Torah, Laws of Idolatry 1:3). God told him to leave his land and promised to make of him a great nation (Genesis 12:1–2). The covenant passed to Isaac and to Jacob, whose twelve sons became the people of Israel.

Moses and Sinai

Judaism as a complete way of life – the commandments, Shabbat, the festivals, the laws of justice and holiness – was given at Mount Sinai after the Exodus. The Ten Commandments open: “I am the Lord your God, who brought you out of the land of Egypt” (Exodus 20:2). Moses taught the Torah to the people and it was passed on, as the first mishnah of Pirkei Avot puts it, to Joshua, the elders, the prophets and the Men of the Great Assembly.

Not a founder religion

For this reason Jews do not speak of a human founder in the way other faiths name theirs. Abraham is “our father”, Moses is “our teacher” (Moshe Rabbeinu) and the greatest of prophets – but the Torah is understood as God’s, given to a whole people who heard the Ten Commandments together.

What historians say

Historians discuss when the religion took the form we know, and many see the Second Temple period and the rabbinic age after it as the time when Judaism as practised today – synagogue, prayer, Mishnah and Talmud – took shape. Tradition sees that development as the Oral Torah unfolding from Sinai.