Under the old covenant, the priests represented the people before God, bringing sacrifices on their behalf to cover their sin and cleanse the temple and tabernacle. The most important work of the priesthood occurred on the annual Day of Atonement, when Israel’s high priest took the blood of the sacrifice into the Holy of Holies to atone for the nation’s sins (Lev. 16). That annual cleansing by the intermediary who represented the people was necessary to maintain the covenant relationship between the Lord and the Israelites.
By the time of the Reformation, there was much focus on the church’s priests as intermediaries between the people and God who offered up a sacrifice of atonement in the Eucharist (the Lord’s Supper) at each Mass. The Reformers objected strongly, for they rightly saw that a continuing priesthood that propitiated (turned away) the wrath of God through the ongoing sacrifice of the Mass was a repudiation of Christ’s office as our High Priest. As we see in today’s passage and many other texts in the book of Hebrews, there is only one priest and intermediary between the people and God—Christ Jesus our Lord (Heb. 2:17).
The Westminster Shorter Catechism explains that “Christ executeth the office of a priest, in his once offering up of himself a sacrifice to satisfy divine justice, and reconcile us to God; and in mak-ing continual intercession for us” (WSC 25). Here we see that our Lord’s priestly work includes both His effectual never-to-be-repeated sacrifice for our sin and His effectual intercession on our behalf.
When we speak of Jesus as our Priest or High Priest, we are referring first to the perfection of His sacrifice. Old covenant priests repeated their sacrifices again and again because the blood of bulls and goats cannot truly atone for the sin of human beings. Only a human being can atone for other human beings, so a man had to die if true atonement was ever to be made. Christ Jesus offered this perfect atonement, suffering and dying as a man to cover our sin. The perfection of His atonement means it cannot and need not be repeated, and any attempt to do so calls into question the sufficiency of His work (Heb. 9–10).
Christ is our all-sufficient Savior because He is our Priest. Not only does He offer the true atonement for our sin, He also ever lives to intercede for us (7:25). It is good news indeed that Christ prays for His people, for it means that He cannot fail to save His elect. Being the Son of God, He knows how to intercede for us before His Father perfectly such that none of His own will ever be lost.