Priests have been part of Christianity since the very beginning, and have their roots in the Old Testament.
One of the most distinctive terms used in the Catholic Church (though sometimes used by other denominations) is the word “priest.” It is the most common term used to identify an ordained member of the clergy and has a rich history in Christianity.
The English word “priest” is derived from the Greek presbyteros, presbyter, meaning “elder.” It is used throughout the Old and New Testaments to identify an individual who offers a sacrifice to God.
The first use of the term is in the book of Genesis to identify the mysterious Melchizedek, who appears out of nowhere in an encounter with Abraham.
Melchizedek, king of Salem, brought out bread and wine. He was a priest of God Most High. He blessed Abram with these words:“Blessed be Abram by God Most High,the creator of heaven and earth;And blessed be God Most High,who delivered your foes into your hand.”Then Abram gave him a tenth of everything. (Genesis 14:18-20)
Later on there develops a Levitical priesthood under Moses, which is maintained for several centuries in a priesthood associated with the Jewish Temple. It is the duty of the Jewish priest to offer sacrifices to God on behalf of the people.
Jesus became known among Christians as the ultimate priest, offering up his own life as a pure sacrifice, substituting the former priesthood with a new priesthood.
[W]hen Christ came as high priest of the good things that have come to be, passing through the greater and more perfect tabernacle not made by hands, that is, not belonging to this creation, he entered once for all into the sanctuary, not with the blood of goats and calves but with his own blood, thus obtaining eternal redemption. (Hebrews 9:11-12)
His priesthood is also connected to that of Melchizedek, as the writer to the Hebrews mentions, “Jesus has entered on our behalf as forerunner, becoming high priest forever according to the order of Melchizedek” (Hebrews 6:20).
This connects Jesus’ sacrifice of his body with the offering of the bread and wine at the Last Supper, inaugurating a new priesthood. The letters of the New Testament constantly refer to this priesthood, explaining how “presbyters” are appointed to various Christian communities.
They appointed presbyters for them in each church and, with prayer and fasting, commended them to the Lord in whom they had put their faith. (Acts 14:23)
Catholic priests follow in this line, offering the unbloody sacrifice of the Mass that is spiritually connected to the bloody sacrifice of Jesus on altar of the cross. The life of a priest is meant to be one of sacrifice, not only in the context of the Mass, but also in his manner of life. Jesus calls each priest to follow in his footsteps, “Whoever wishes to come after me must deny himself, take up his cross, and follow me” (Matthew 16:24).
In this way, even the laity are called to a type of priesthood, as the Catechism of the Catholic Church explains, “The whole Church is a priestly people. Through Baptism all the faithful share in the priesthood of Christ. This participation is called the ‘common priesthood of the faithful'” (CCC 1591). This common priesthood of the “faithful is exercised by the unfolding of baptismal grace –a life of faith, hope, and charity, a life according to the Spirit” (CCC 1547).
While not everyone is called to the ministerial priesthood and the offering of the Mass, all baptized Catholics are called to offer their lives daily as a sacrifice to God.
To be a priest entails sacrifice, and that definition has always been true throughout history.