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 Rabbinic Judaism
Orthodox Judaism does not accept the scholarly view that Rabbinic Judaism came into being in the post-Second Temple era. Rather, it sees the Judaism of this period as continuing organically from the religious and cultural heritage of the Israelites, stemming from the Revelation at Sinai onwards. According to this view, while the title "Rabbi" was not used earlier, Moses was the first rabbi (and is commonly referred to by Orthodox Jews as "Moses our Rabbi"), with the knowledge and laws received at Sinai being passed down from teachers to students through the era of the Judges, and the prophets (most of whom are seen as the "rabbis" of their time), through the Sages of the late Second Temple period, and continuing until today.