A priest is a person who serves as a religious leader and performs sacred duties. The word "priesthood" refers to both the role of being a priest and the group of people who serve as priests.
The modern word “priest” comes from the French prêtre and German priester. In churches with bishops, this term describes clergymen (Orthodox, Roman Catholic, and Anglican). It is also used in the description of the whole church as “a royal priesthood” (1 Peter 2:9).
To understand what priesthood means fully, we need to look at how the Bible talks about priests and priesthood. We also need to look at how Christian teachers and writers have explained priesthood over time.
Priesthood in the Old Testament
When God made an agreement (covenant) with the people of Israel, God called them to be a “kingdom of priests.” So, they were a people set apart to God (Exodus 19:6). There were three orders for the priestly activities—high priest, priest, and Levite. “High priests” and “priests” were male descendants of Aaron, who was a Levite (Numbers 3:10). “Levites” were other male members of the tribe of Levi.
The main functions of the priesthood took place in the temple. Priests managed the ceremonial items and performed the sacrifices. They wore special, symbolic clothing called vestments while performing their duties. They were also teachers who passed on the sacred traditions of the nation. They also instructed the people in matters such as medical information (Leviticus 13–15).
The high priest was the spiritual leader of Israel. He had special functions. These included entering the the Most Holy Place (also called the Holy of Holies) on the Day of Atonement (Leviticus 16). The Levites assisted the priests and served the congregation in the temple. They sang the psalms and kept the temple courts clean. They helped to prepare certain sacrifices and offerings, and also functioned as teachers.
Through these three groups, the priests helped all the people of Israel worship God. They also prayed to God for themselves and others, and learned God's will. This system was like how a the leader of a family would lead in worship at home, but on a larger scale and with more formal ceremonies at the temple.
Priesthood in the New Testament
It is notable that the term “priest” to describe leaders in the early church. The word "priest" only appears when talking about Jewish or pagan priests (Acts 4:1, 6; 14:13). The book of Hebrews explains that Jesus Christ perfectly fulfills the role of the Old Testament priesthood in three important ways:
God himself chose Jesus to be high priest (Hebrews 5:4–6). Jesus's priesthood is greater than Aaron's priesthood (chapter 7).
Jesus can sympathize with the weaknesses of sinful people. He "was tempted in every way" like them, but was without sin (4:15; 7:26).
Instead of offering animal sacrifices to take away sin, he offers himself. He is the sinless sacrifice who takes away sin. This sacrifice only needed to happen once (7:27; 9:24–28; 10:10–19).
Jesus fulfills the sacrificial system of the Old Testament. The unique, unrepeatable, and unlimited sacrifice of Jesus also completes it. Having risen from the dead, he is a priest forever (Hebrews 7:17). He remains the same yesterday and today and forever (13:8). Part of his high priesthood is to intercede for his people (7:25). He brings people to God as a mediator through a new and better covenant (7:22; 8:6; 9:15). Only through Jesus are sinful human beings able to enter the holy presence of God. Only through Jesus are they accepted as children of God (John 14:6; 2 Corinthians 5:18–20; 1 Timothy 2:5). So, Christians do have a priesthood. Yet, it is only in and through Jesus Christ, their high priest and Mediator.
The Priesthood of Believers
The New Testament describes those who believe and follow Jesus as “being built… to be a holy priesthood, offering spiritual sacrifices acceptable to God through Jesus Christ” (1 Peter 2:5). They are “priests to his God and Father” (Revelation 1:6). They are “a kingdom and priests to serve our God” (5:10). They "will be priests of God and of Christ, and will reign with Him for a thousand years” (20:4–6).
So, what does the "priesthood of believers" mean in the New Testament? We can define the high priesthood of Jesus in two ways:
Jesus has complete dedication and obedience to God his Father.
Jesus has unlimited compassion for his fellow human beings.
His sacrificial death on the cross is the center of his priesthood. The priesthood of believers finds its basis in his sacrificial death and union with him. This priesthood is their sacrificial obedience to God. It involves spiritual worship and love of God. It also includes compassion and prayer for their fellow human beings.
Paul wrote, “offer your bodies as living sacrifices, holy and pleasing to God, which is your spiritual service of worship” (Romans 12:1). Christians offer their whole bodies to Jesus. Each local church offers itself wholly to Jesus. Jesus offers his whole body (the church) to God the Father. So, Jesus shows us both what it means to be a priest and how to serve as priests under him as our high priest. The Holy Spirit helps believers serve as priests by:
living in their hearts,
giving them power to serve God in ways that please him, and
helping them worship God properly.