I would like to introduce a short series which briefly examines the Jewish traditions from which Christianity emerged. It will begin with the Zealots.
Josephus refers to the Zealots as the “fourth Jewish philosophy,” founded by Judas the Galilean (in 6 A.D.); he strongly contends that all succeeding troubles including the burning of the Temple can be traced to his teaching. It should be noted that Josephus, who had turned to the Romans, is most certainly offering a politically acceptable assessment of these sworn enemies of Rome that he calls “bandits.” It is difficult to discover reliable information about the zealots when Josephus, who opposed them bitterly, is the primary, if not only source.
Josephus relates that the name “zealot” was self-ascribed by this Jewish sect, “for Zealots they called themselves, as if they were devoted to good works, not zealous for all that was vile, vile beyond belief.” (Wars IV.161). The designation has frequently come to be used of all who rebelled against Rome with force.
The movement was both religious and political. One might describe the Zealots as a sect very much preoccupied with Jewish nationalism. The common ground for all the Jewish parties was the Torah. But unlike the Pharisees or Sadducees, the Zealots offered no new conception of the Law; they were not out to interpret it, just to fight for it. They would assert that the Law demanded YHWH be only king that the Jews acknowledged and that they should establish His reign by rooting out paganism and by breaking from the tyranny of Rome. The Torah made separation from Gentiles necessary, exalted Israel as the chosen of God, and promised triumph. The zealots sought to enforce these beliefs by violence of any kind.
The Zealots favored armed rebellion against Rome. They held to the idea that Roman rule was incompatible with Jewish freedom, and that the Jews should be free of Roman control. This culminated, eventually in an actual revolt, the Great Jewish Revolt. Zealots, especially those in the Iudaea Province, captured Jerusalem and were able to hold it until 70 CE. Rome eventually retook Jerusalem, leading to the destruction of the Second Temple.
The Zealots do not figure prominently in the biblical records, but there are references to them. One of the twelve, Simon Zelotes (Mark 3:18) was possibly a Zealot at one point. Barabbas was likely a zealot; the term used to describe him in John 18:40 is the same word used by Josephus to describe the Zealots.
Jesus never openly refers to the Zealots. His statement that men try to take the kingdom by force (Matthew 11:12) has been interpreted as a criticism of such misguided zeal. Whether it refers to the Zealots or not is debated.