Judaism
Around the 1st century CE, there were several small Jewish sects: the Pharisees, Sadducees, Zealots, Essenes, and Christians. After the destruction of the Second Temple in 70 CE, these sects vanished. Christianity survived, but by breaking with Judaism and becoming a separate religion; the Pharisees survived but in the form of Rabbinic Judaism (today, known simply as "Judaism"). The Sadducees rejected the divine inspiration of the Prophets and the Writings, relying only on the Torah as divinely inspired. Consequently, a number of other core tenets of the Pharisees' belief system (which became the basis for modern Judaism), were also dismissed by the Sadducees. (The Samaritans practiced a similar religion, which is traditionally considered separate from Judaism.)
Origins of Judaism
Judaism has its origins in the Iron Age Kingdom of Judah and in Second Temple Judaism. It has three essential and related elements: study of the written Torah (the books of Genesis, Exodus, Leviticus, Numbers, and Deuteronomy); the recognition of Israel (defined as the descendants of Abraham through his grandson Jacob) as a people elected by God as recipients of the law at Mount Sinai, his chosen people; and the requirement that Israel live in accordance with God's laws as given in the Torah.