His organization of local government and his efforts to maintain law and order brought him into collision with the Zealots and especially with John of Giscala, one of their leaders.
My friends never had occasion to vindicate any one circumstance of my character and conduct; not but that the zealots, we may well suppose, would have been glad to invent and propagate any story to my disadvantage, but they could never find any which they thought would wear the face of probability.
Judas and his zealots were thus able to maintain their prominence and gradually to increase their power.
The result of this alliance between a revolutionary and a Pharisee was the formation of the party of Zealots, whose influence - according to Josephus - brought about the great revolt and so led to the destruction of Jerusalem in 70.
So far as this influence extended, the Jewish community was threatened with the danger of suicide, and the distinction drawn by Josephus between the Pharisees and the Zealots is a valid one.