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.)
Sectarian discrimination
Sectarianism also exists between Orthodox and Reform Jews, with orthodox Jews often characterizing reform Jews as being non-religious, disobeying the Torah, rarely attending shul and adopting semi-Christian styles of worship. Reform Jews, on the other hand, often view the orthodox as being intolerant of them and of other religions, placing legalistic rules such as the observance of the Sabbath above ethical obligations, being cult-like and hostile to change.