In the OT the priests were intermediaries between the people and their all‐powerful God. Their main function was to offer sacrifices, with a subsidiary duty until the Exile, of teaching the Law. They were also in charge of Urim and Thummim, the sacred lots, carried by the priests in a front pocket (Exod. 28: 30). During the period of the Judges, priests of the tribe of Levi were particularly valued (Judg. 17: 10). When worship was centralized at Jerusalem, local shrines were closed and many Levites who were not descendants of Aaron had no employment (Deut. 12: 12 f.), and were not accepted at Jerusalem as true priests. They were suspected of having become tainted with Canaanite practices in their rural shrines, and so in the Temple were relegated to an inferior status (Ezek. 44: 10–14). Priests were superior as being descendants of Zadok (Ezek. 48: 11). Post‐exilic literature (Mal. 2: 4–7) suggests that both priests and Levites were accorded a common descent from Levi and as such the Levites, though distinct from priests, had important duties at the services (1 Chron. 16: 4–27) and in teaching (2 Chron. 17: 7–9). In the NT the distinction between priests and Levites is maintained (Luke 10: 31, 32).
Chief priests, together with elders and scribes, comprised the Jerusalem Sanhedrin (Mark 14: 55) before whom Jesus appeared before being sent for trial by Pilate. The ‘chief priests’ were members of priestly families from whom the ‘high priest’ (Caiaphas, Matt. 26: 3) was chosen. In the NT Church the whole body of Christians were regarded as a ‘royal priesthood’ (1 Pet. 2: 9) not in the sense of a ruling or tyrannical priesthood but as a body charged, like a king, to mediate blessings to the world and to offer spiritual sacrifices.