Christianity did not develop in a vacuum. Nor did it simply come into existence with the death of Jesus and his alleged resurrection (more on that later).
When the apostle Paul (who lived Saul of Tarshish and true founder of Christianity) took his gospel message of Jesus to the Jews, they were not interested. When those efforts failed, he tried to convert Romans. By the end of the 1st Century it is estimated that 10% of the Roman Empire had already converted to some form of Judaism. Roman political intrigues and assassinations along with barbaric torture of its citizens coupled with general moral decay and pagan hedonism led many in the empire to seek relief. They found it in Judaism and early Christianity.
Highlights: Christianity developed within Roman Empire. Paul was true founder of the religion. Wrote 17 of the 27 books of the Christian Scriptures (known as New Testament). Paul initially persecuted the early Christians but undergoes conversion.
On the other hand, there was great religious turmoil in Israel. With the Roman occupation of Judea during the 1st Century C.E., several movements opposing the mainstream Pharisee (as in Hillel, Shammai and Rabban Gamliel) Torah leaders emerged. Competing Jewish sects, some with Messianic aspirations, included the Sadducees, Essenes, Biryonim (Zealots), the Ebionites, and Samaritans,
The famous historian, Josephus Flavius (War II:118-168 and Ant:169-172 XVIII), actually mentions only four different Jewish sects during the first century:
Pharisees
The Pharisees, unlike the Sadducees, maintained the validity of the Oral as well as the Written law. They were affectionate and harmonious in their dealings with others (War II:8,14 [166]), and especially respectful to their elders (Ant XVIII:13 [12]), They enacted rabbinic legislation to protect many institutions of Jewry that were threatened by Roman persecutions and, at times, were willing to adapt the law to changing circumstances. They believed in an afterlife and in the resurrection of the dead. By the first century C.E., the Pharisees came to represent the beliefs and practices of the majority of Palestinian Jewry.
Sadducees
The Sadducees were priestly and aristocratic families who Josephus described as “argumentative,” (Ant XVIII:1,4 [16], "boorish" and "rude" both to each other and aliens (War II:9,14 [166] They had "the confidence of the wealthy" but not the populace (Ant XIII:1,4 [298]. They dominated the Temple worship and its rites, including the sacrificial offerings. The Sadducees only recognized precepts derived directly from the immortality of the soul, the resurrection of the body, and the existence of angels. The Sadducees were unpopular with the common people, as they became tax collectors and agents of the hated Romans.
Essenes
The Essenes were a separatist group, some of whom formed an ascetic monastic community and retreated to the wilderness of Judea. They shared material possessions and occupied themselves with disciplined study, worship, and work. They believed that the cataclysmic rule of Roman was portentous that the apocalypse was at hand, and that the Messiah would lead the forces of light against the evil forces of darkness . Many scholars equate this group with the Dead Sea Scroll Sect, and some believe Christianity grew out of this movement.
Biryonim (Zealots)
This group agreed with the Pharisees in most respects except that it followed the anarchistic ideology "No king but God!" They may have consisted of the Sicarii, fierce warriors (Latin, sica = dagger), who were not opposed to using their weapons on Jewish collaborators of the Romans. The Biryonim were also known as The Zealots. The fall of Masada in 73 C.E, and mass suicide of its Jewish inhabitants, is often associated with the Zealots and Sicarii.
Highlights: During the 1st Century C.E. Judaism had become fractionalized. Some groups advocated more cooperation with the occupying Romans, while others advocated rebellion. The Pharisees were the only ones who most remained faithful to the Laws of Moses, and traditional Judaism.
Life in 1st Century Judea under Roman occupation was intolerable, to say the least. Institutions from the High Priesthood, to the selection of political leaders were under their strict control of the Roman authorities. They oppressed the Jewish community with their swords and stifling taxes. Outbreaks of protest and rebellion against Roman occupation, initiated by some of the groups mentioned above, were suppressed ruthlessly. Judea was looking for a champion. The Pharisees, by and large, deplored violence. What could they do?
At this time, Messianic fervor heightened spawning strands of messianism and charismatic figures with diverse plans for dealing with Roman occupation. Idealistic yearnings for a new “World Order,” were gaining voice in Judea. Joseph Klausner, professor of Hebrew literature and history at the Hebrew University and once candidate for President of Israel in 1949, wrote a very scholarly book called Jesus of Nazareth (New York Macmillian 1943) where he coined a term for this period of Jewish history – “the Messianic Chain.” According to Klausner it was punctuated with the following themes:
“Signs of nearness of the Messiah’s coming, the forerunner Elijah, the trumpet of deliverance, the ingathering of the exiles, the conversion of unbelievers, the War with Gog and Magog, the millennial rule of the Messiah, the renewal of the world, the Day of Judgment, the resurrection of the dead, and the World to Come or eternal life.”
In fact, the name Jesus, or Yeshu, according to the accepted Hebrew equivalent, was not an unusual name given to Jewish children by fervently optimistic parents, who waited for the True Deliverer to vanquish the hated Romans and restore the Davidic line to the throne of Judea and Israel. It was in this backdrop that the personality of Jesus resonated with some of the people around 30 C.E.
Highlights: Roman oppression spawned a number of Messianic groups each with a plan on how to repulse the hated Romans from Judea. One of these movements hailed Jesus from Nazareth as its leader.