Köln-Tora-und-Innenansicht-Synagoge-Glockengasse-040" by Horsch, Willy - eigenes Foto (Zeughaus). Licensed under CC BY 3.0 via Wikimedia Commons
They were the equivalent of our modern government, senior civil servants and diplomats, governing domestically, collecting the Temple tax and tithes, which ran the institution of Judaism both from the Jews at home and those in the Diaspora. They also administered the army as well as the Temple whose rituals were led by priests who were not necessarily Sadducees.
The Sadducees were not the same as The Sanhedrin. This which was the political and religious legislative body of Judaism and met in the Temple. Pharisees were also members of it. Pharisees were normally highly religious laymen who administered the local synagogues and study centres, teaching Jewish boys to read and study the Hebrew scriptures. They could also be priests, in the Temple.
The Sadducees seem to have been partly right about one thing : the authority of the word of God, but they did not believe in Him as strongly as the Pharisees thought they did - or at least those Pharisees who were not regarded as "whitewashed tombs" by Jesus. They were what we might call 'liberals' today who tend to rationalise God into passive and ineffective remoteness. The worldly Sadducees rejected the burdensome Oral Law, known as the Mishnah, built up by the Pharisees (which Jesus also rejected). They saw the Torah, the first five books of our Bible as the only rule for the rituals of Judaism.
According to Josephus, the Romano-Jewish historian, the Sadducees did not believe in fate - that all our days are planned out for us before any of them start (which The Psalms clearly state). They considered that Man has complete free will. They did not believe that the soul is immortal or passes to heaven or hell. There were, for them, no rewards for good deeds, or punishments for evildoers. They did not believe in resurrection, unlike the Pharisees, but instead supposedly believed in the traditional Jewish concept of Sheol, a kind of Jewish Hades, mentioned by Job in the Old Testament.
Josephus was a Pharisee and he claims that the Pharisees believed that only the soul alone was immortal and that the souls of good people would be reincarnated and pass into other bodies while the souls of the wicked will suffer eternal punishment.
By contrast, Jesus's teaching was radically different from both these sects. He would have been in close contact with Pharisees via his local synagogue and was 'taught' by them yet, at the start of His Ministry he 'came out' with His radical teaching which, though based on the written Word, contradicted the man-made ideas of both the Pharisees and the Sadducees:
- the whole of Scriptures is authoritative, not just the first five books of the Bible, including His own words which "will never pass away"
- the whole Scriptures cannot be broken i.e. even if the written way of handling them has passed, the principle behind them remains edifying - such as the holiness of God. (For example, stoning for adultery appears in the Bible, not incidentally in the Koran, but even in ancient times, it was rarely actually carried out. Jesus clearly states in that stoning a woman for adultery can only be done by completely innocent people - so He supports the written Word in principle, but ends ancient practice).
- we are both free and not free - yet completely responsible for what we choose
- there are rewards for good deeds, in the body, even though good deeds do not achieve salvation. there is eternal punishment, for evil deeds.
- there is a resurrection of the body and soul together - not just the soul which was a Greek idea. The body and soul stay together in Heaven - transformed.