"And concerning these things it is that great disputes and differences have arisen among them, while the Sadducees are able to persuade none but the rich, and have not the populace obsequious (obedient or giving deference) to them, but the Pharisees have the multitude on their side." (Antiquities of the Jews, Book 13, Chapter 10)
The Sadducees believed the only source of divine authority was the written Torah (law of God or first five books of the Bible) and rejected the Oral Traditions held by the Pharisees. Their priestly responsibilities included the daily offering of sacrifices at the temple and presiding over the sacrifices during the three great pilgrimage feasts (Passover, Pentecost and Feast of Tabernacles) held in Jerusalem. Their political responsibilities included administering the Jews in Judea, collecting taxes, equipping and leading the army, and regulating relations with the Roman Empire.
It was their operation of the temple that Jesus indirectly criticized when, near the beginning of his ministry, he cast out the money changers and those selling goods from the temple's outer court (court of the Gentiles - John 2:13 - 17). Even after he cleansed the temple Jesus had to do it again, three years later, near the end of his ministry (Mark 11:15 - 17, Luke 19:45 - 46, Matthew 21:12 - 13).
While they were critical of Jesus during his ministry, their opposition and hostility toward the gospel seemed to grow and become more vocal after his death. One reason for this marked increase was likely due to their firm belief that there was no resurrection from the dead (Mark 12:18 - 27). This conflicted with the primary message of the early New Testament church, which centered around the suffering, death and resurrection of Jesus the Messiah.
Beliefs and Practices
The Sadducees did not believe in the resurrection of the dead (Mark 12:18 - 27) whereas the Pharisees believed one would occur in the future (Acts 23:6 - 8, 18) during the Messianic age. They also did not believe in the existence of angels and spirit beings in general, while the Pharisees did believe and even taught such spirits could communicate with man (Acts 23:8 - 9). According to the historian Josephus, they believed humans had complete free will, while the Pharisees adhered to the belief in free will but left room for God to have foreknowledge of mankind's destiny. They rejected the Oral Tradition held by the Pharisees and the doctrines it taught. The believed the only source of divine authority was the written Torah.
"What I would now explain is this, that the Pharisees have delivered to the people a great many observances by succession from their fathers, which are not written in the laws of Moses; and for that reason it is that the Sadducees reject them, and say that we are to esteem those observances to be obligatory which are in the written word, but are not to observe what are derived from the tradition of our forefathers." (Antiquities of the Jews, Book 13, Chapter 10)
While the temple priesthood prided itself on its aristocracy of blood, the Pharisees instead were proud of their superiority in learning.
The Sadducees believed in an excessively stringent lifestyle and a very strict literal interpretation of God's written law while the Pharisees used both the written and oral law (or traditions) to decide how to apply God's words to life. They, in general, were conservative, aristocratic monarchists, while the Pharisees were eclectic, popular and more democratic.
The significant difference between the Sadducean and Pharisaic view of God's law and its application to life can best be seen by the following example. The Bible says "eye for eye, tooth for tooth, hand for hand . . . " (Exodus 21:24). The Pharisaic application of this verse was that a monetary compensation of the value of the lost eye (or tooth or hand) should be paid to the injured party. The Sadducees interpretation of this verse meant that those who caused the loss of an eye (or tooth or hand) should be punished by losing one of their own eyes, teeth or hands.