Satan
Each sect of Judaism has its own interpretation of Satan's identity. Conservative Judaism generally rejects the Talmudic interpretation of Satan as a metaphor for the "yetzer hara", and regard him as a literal agent of God. Orthodox Judaism, on the other hand, outwardly embraces Talmudic teachings on Satan, and involves Satan in religious life far more inclusively than other sects. Satan is mentioned explicitly in some daily prayers, including during Shacharit and certain post-meal benedictions, as described in Talmud and the Jewish Code of Law. In Reform Judaism, Satan is generally seen in his Talmudic role as a metaphor for the "yetzer hara" and the symbolic representation of innate human qualities such as selfishness.
Origins of Christianity
Several Jewish sects are known to have existed during the 1st century CE: the Essenes, Pharisees, Sadducees, Zealots, and Christians. After the destruction of the Second Temple in 70 CE, most of these sects vanished, but Christianity and the Pharisees survived, with Christianity gradually becoming a separate religion, and the Pharisees developing into Rabbinic Judaism, or simply Judaism. Rather than a sudden split, there was a slowly growing chasm between Christians and Jews in the 1st centuries, and it took centuries for a complete break to manifest.