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.)
Historical background of the New Testament
Historians seek to understand where Jesus and his followers fit among other Jewish factions at the time. According to the Jewish-Roman historian Flavius Josephus, the three parties in contemporary Judaism were the Pharisees, the Sadducees and the Essenes, the last of these three being apparently marginalized and in some cases retired to quasi-monastic communities. Josephus also speaks of a "Fourth Movement", "Zealots", "Lestai" or "Sicarii".
The Pharisees were a powerful force in 1st-century Judea. Early Christians shared several beliefs of the Pharisees, such as resurrection, retribution in the next world, angels, human freedom, and Divine Providence. After the fall of the Temple, the Pharisaic outlook was established in Rabbinic Judaism. Some scholars speculate that Jesus was himself a Pharisee. In Jesus' day, the two main schools of thought among the Pharisees were the House of Hillel, which had been founded by the eminent Tanna, Hillel the Elder, and the House of Shammai. Jesus' assertion of hypocrisy may have been directed against the stricter members of the House of Shammai, although he agreed with their teachings on divorce. Jesus also commented on the House of Hillel's teachings (Babylonian Talmud, Shabbat 31a) concerning the greatest commandment and the Golden Rule. Historians do not know whether there were Pharisees in Galilee during Jesus' life, or what they would have been like.