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.)
Jewish religious movements
The Jewish denominations themselves reject characterization as sects. Sects are traditionally defined as religious subgroups that have broken off from the main body, and this separation usually becomes irreparable over time. Within Judaism, individuals and families often switch affiliation, and individuals are free to marry one another, although the major denominations disagree on who is a Jew. It is not unusual for clergy and Jewish educators trained in one of the liberal denominations to serve in another, and left with no choice, many small Jewish communities combine elements of several movements to achieve a viable level of membership.