Question: "What were the chief priests?"
Answer: The priesthood began when the nation of Israel left Egypt during the Exodus. In Numbers 3:12–13 the Lord set apart the entire tribe of Levi for special service. From the Levites came the priests, and among the priests were the high priest and, in Luke 19:47, “chief priests.”
Moses, Aaron, and Miriam were all from the tribe of Levi, as were thousands of other men and women. God indicated that the high priest had to be a descendant of Aaron. Priests were Levites, but only some of the Levites belonged to the Aaronic priesthood. Exodus 29:7–9 states, “Take the anointing oil and anoint him by pouring it on his head. Bring his sons and dress them in tunics and fasten caps on them. Then tie sashes on Aaron and his sons. The priesthood is theirs by a lasting ordinance. Then you shall ordain Aaron and his sons.” Only the high priest, or chief priest, could enter the Most Holy Place once a year on the Day of Atonement (Yom Kippur). The other Aaronic priests served in rotating “courses” so that they could all minister in the Holy Place and offer sacrifices.
The rest of the Levites served in other ways. The other sons of Levi were involved in carrying the ark and the various parts of the tabernacle. After the temple was built, the Levites were involved in caring for the temple. Numbers 3 provides information about them.
Acts 23 demonstrates that the priesthood was not functioning as outlined in the Pentateuch. The Sanhedrin, for example, was not a biblical concept. It was probably begun about 70 BC by Alexander Janneaus, the Hasmonean king of Judea. Eventually, the Sanhedrin consisted of 70 or 71 elders and scholars, including the high priest (usually the president of the body), other Levitical priests, Sadducees (of the tribe of Levi), and Pharisees. The purpose of the Sanhedrin was to act as a court in making decisions regarding the Law.
The Sadducees were in control of the temple. They were wealthy, aristocratic, and liberal in their theology. They did not believe in the resurrection or in angels, and they only accepted the first five books of the Bible. The Pharisees, in contrast, were not from the tribe of Levi but could be from any tribe. As a sect, they were ritualists, legalists, separatists, and zealots. They accepted the entire Old Testament as Scripture.
In Acts 23:2 Paul is on trial. Ananias is identified as the high priest in charge of the proceedings. Then, verse 14 mentions “the chief priests and the elders.” The “chief priests” were probably Sadducees and others in the Sanhedrin. Both the NIV and NASB refer to “chief priests” in the plural. Other translations call them “leading priests” or “princes of the priests.” The group probably included Ananias and other priests who wielded a certain amount of political power and influence.