The role of the priests in the Bible is a multifaceted one, deeply rooted in the religious, social, and cultural life of ancient Israel. Priests served as mediators between God and His people, performing sacred rituals, teaching the Law, and maintaining the sanctity of the worship practices. Their duties and responsibilities are outlined primarily in the Old Testament, with significant implications for understanding the priesthood in the New Testament.

Old Testament Priesthood

The priesthood was established by God through Moses, with Aaron and his descendants appointed as the first priests (Exodus 28:1). The tribe of Levi was set apart for priestly duties, and within this tribe, the family of Aaron was designated for the high priesthood. The primary role of the priests was to serve in the Tabernacle, and later in the Temple, where they conducted sacrifices, offerings, and other rituals as prescribed by the Law.

1. Sacrificial Duties: Priests were responsible for offering sacrifices on behalf of the people. These included burnt offerings, sin offerings, and peace offerings, among others. Leviticus 1-7 provides detailed instructions on how these sacrifices were to be conducted. The priests acted as intermediaries, presenting the people's offerings to God and seeking atonement for their sins.

2. Teaching the Law: Priests were also tasked with teaching the Israelites the statutes and commandments of God. As stated in Leviticus 10:11, "You must teach the Israelites all the statutes that the LORD has given them through Moses." They were custodians of the Law, ensuring that the people understood and adhered to God's commands.

3. Maintaining Ritual Purity: The priests were charged with maintaining the ritual purity of the sanctuary and the people. This involved overseeing purification rites and diagnosing and treating cases of leprosy and other impurities (Leviticus 13-14).

4. Festivals and Holy Days: Priests played a central role in the observance of religious festivals and holy days, such as Passover, the Day of Atonement, and the Feast of Tabernacles. They led the community in worship and ensured that the celebrations were conducted according to divine instructions.

5. Judicial Functions: In some cases, priests served as judges, particularly in matters related to religious law and disputes (Deuteronomy 17:8-12). They were seen as authorities on the Law and were consulted for their wisdom and guidance.

New Testament Priesthood

In the New Testament, the concept of priesthood undergoes a significant transformation with the advent of Jesus Christ, who is described as the ultimate High Priest. The Epistle to the Hebrews elaborates on this, stating, "But when Christ came as high priest of the good things that have come, He went through the greater and more perfect tabernacle that is not made by hands, that is, not of this creation" (Hebrews 9:11).

1. Christ as High Priest: Jesus is portrayed as the fulfillment of the Old Testament priesthood, offering Himself as the perfect sacrifice for sin. His priesthood is eternal and unchanging, as He "always lives to intercede for them" (Hebrews 7:25).

2. The Priesthood of All Believers: With Christ's sacrifice, the New Testament introduces the concept of the priesthood of all believers. 1 Peter 2:9 states, "But you are a chosen people, a royal priesthood, a holy nation, a people for God’s own possession, to proclaim the virtues of Him who called you out of darkness into His marvelous light." This signifies that all Christians have direct access to God and are called to serve Him in various capacities.

3. Role in the Early Church: While the New Testament does not establish a formal priesthood akin to the Old Testament, it does recognize roles of leadership and service within the church, such as elders and deacons, who are tasked with shepherding the flock and teaching the Word (1 Timothy 3:1-13).

The role of the priests, both in the Old and New Testaments, underscores the importance of mediation, sacrifice, and teaching in the relationship between God and His people. Through the priesthood, God provided a means for His people to approach Him, understand His will, and live in accordance with His commands.