One perspective of Jewish religious groups in Jesus’ time and Jesus, from Huston Smith’s excellent The World’s Religions:
Unlike the Sadducees, [Jesus] wanted change. Unlike the Essenes, he stayed in the world. Unlike the advocates of the military option, he extolled peacemakers and urged that even enemies be loved. It was the Pharisees that Jesus stood closest to, for the difference between them was one of emphasis only. The Pharisees stressed Yahweh’s holiness, while Jesus stressed Yahweh’s compassion; but the Pharisees would have been the first to insist that Yahweh was also compassionate, and Jesus that Yahweh was holy.
…Jesus subscribed to [much of the Pharisees’ program for holiness, as God demanded], but there was an important feature of the holiness program he found unacceptable: the lines that it drew between people. Beginning by categorizing acts and things as clean or unclean…, the holiness code went on to categorize people according to whether they respected those distinctions. The result was a social structure that was riven with barriers: between people who were clean and unclean, pure and defiled, sacred and profane, Jew and Gentile, righteous and sinner… Jesus saw social barriers as an affront to [Yahweh’s] compassion. So he parleyed with tax collectors, dined with outcasts and sinners, socialized with prostitutes, and healed on the sabbath when compassion prompted doing so.
The World’s Religions has proved an eye-opening resource on Hinduism, Buddhism, Taoism, and Judaism. Now it is giving me some historical insight and conceptual perspectives on my own faith.