Abraham (Avraham) was the first Jew, the founder of Judaism, the physical and spiritual ancestor of the Jewish people, and one of the three Patriarchs (Avot) of Judaism.

Although Adam, the first man, believed in one God, most of his descendents prayed to many gods. Abraham, then, rediscovered monotheism. 

Abraham's faith in the One God was tested when God commanded him to sacrifice his son Isaac (Yitzhak). Abraham was about to fulfill God's commandment and sacrifice his son when the Angel of God stopped him. Abraham's faith in God has been a model for all future generations of Jews.