Shorter Catechism Q. 25. How doth Christ execute the office of a priest? A. 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 making continual intercession for us.
Commentary: A prophet is a person who speaks on behalf of God to the people. A priest, however, operates in the other direction. He is someone who speaks to God on behalf of the people. More specifically, a biblical high priest is someone “chosen from among men” who “is appointed to act on behalf of men in relation to God, to offer gifts and sacrifice for sins (Heb. 5:1).”
Jesus was not a Levitical priest because he was from the tribe of Judah. Nonetheless, he did not make himself a priest but was appointed by God to be a priest after the order of Melchizedek (Heb. 5; Ps. 110). How then did Jesus do (and continue to do) the work of a priest? At least two ways.
First, Jesus offered up himself as “a sacrifice to satisfy divine justice, and reconcile us to God.” A priest reconciles sinners to God by offering up a sacrifice for sins. For there is no forgiveness without the shedding of blood. Jesus, however, did not offer up an unblemished animal, as did the Levitical priests, but himself. He is both priest and sacrifice. He is, therefore, the way, the truth, and the life. No one comes to the Father except through him.
Second, Jesus makes “continual intercession for us.” He doesn’t have to continually offer up sacrifices for sin, as did the Levitical priests, because “he did this once for all when he offered up himself (Heb. 7:27).” Nevertheless, we still need to receive the benefits of his once and for all sacrifice because we still commit sins. In other words, we still need Jesus to be our high priest, that is, we still need him to intercede for us, which is exactly what he does for us in heaven (Heb. Heb. 7:25). Thus, John says that if anyone does sin “we have an advocate with the Father, Jesus Christ the righteous. He is the propitiation for our sins (1 John 2:1-2).” This means that when we do sin, we don’t need to offer up a sacrifice for our sins, but rather we need to confess our sins. And if we confess our sins, God is faithful and just to forgive us our sins and to cleanse us from all unrighteousness (1 John 1:9).