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.)
Essenes
The Jewish historian Josephus records that Essenes existed in large numbers, and thousands lived throughout Roman Judaea, but they were fewer in number than the Pharisees and the Sadducees, the other two major sects at the time. The Essenes lived in various cities but congregated in communal life dedicated to voluntary poverty, daily immersion, and asceticism (their priestly class practiced celibacy). Most scholars claim they seceded from the Zadokite priests.