“So, Aaron shall bear the name of the sons of Israel in the breastpiece of judgement on his heart, when he goes into the Holy Place, to bring them to regular remembrance before the LORD. And in the breastpiece of judgement you shall put the Urim and the Thummim, and they shall be on Aaron’s heart, when he goes in before the LORD. Thus, Aaron shall bear the judgement of the people of Israel on his heart before the LORD regularly.”Exodus 28:29-30
The purpose of the beauty of Aaron’s holy garments is not to glorify himself. The whole point of them is for Aaron, the high priest, to bring the people of Israel before Yahweh with each of their tribes represented on the various jewels (see especially vv. 15-28). In God’s eyes, His people are these precious jewels. The high priest and the other Levitical priests are to bear all the people of Israel and their sins before God, who repeats this law in Numbers 18:21-23, “‘To the Levites I have given every tithe in Israel for an inheritance, in return for their service that they do, their service in the tent of meeting, so that the people of Israel do not come near the tent of meeting, lest they bear sin and die. But the Levites shall do the service of the tent of meeting, and they shall bear the iniquity.'”
And now, we have a greater High Priest:
Since then, we have a great high priest who has passed through the heavens, Jesus, the Son of God, let us hold fast our confession. For we do not have a high priest who is unable to sympathise with our weaknesses, but one who in every respect has been tempted as we are, yet without sin. Let us then with confidence draw near to the throne of grace, that we may receive mercy and find grace to help in time of need.
For every high priest chosen from among men is appointed to act on behalf of men in relation to God, to offer gifts and sacrifices for sins. He can deal gently with the ignorant and wayward since he himself is beset with weakness. Because of this he is obligated to offer sacrifice for his own sins just as he does for those of the people. And no one takes this honour for himself, but only when called by God, just as Aaron was. So also, Christ did not exalt Himself to be made high priest, but was appointed by Him who said to Him, “You are My Son, today I have begotten You” [Psalm 2:7]; as He says also in another place, “You are a priest forever, after the order of Melchizedek” [Psalm 110:4]. In the days of His flesh, Jesus offered up prayers and supplications, with loud cries and tears, to Him who was able to save Him from death, and He was heard because of His reverence. Although He was a son, He learnt obedience through what He suffered. And being made perfect, He became the source of eternal salvation to all who obey Him, being designed by God a high priest after the order of Melchizedek.Hebrews 4:14-5:10
In short, “after the order of Melchizedek” essentially means God can do what He wants and has made Christ High Priest just as the mysterious figure, Melchizedek, was high priest before the order of the Levites (Genesis 14:17-24). When God gave Israel the Law, only Levites could be priests; but before the Levitical institution even existed, a mysterious man named Melchizedek was a high priest. God doesn’t need the Levitical order to make high priests. He made a high priest before the birth of the tribe of Levi, and He can make a high priest after their obsoletion.
Moving on, just as Aaron bore the judgement of Israel on his heart when he entered the Holy of Holies, so Christ bore the judgement—the sins—of the whole world when He laid on the cross (Hebrews 9:11-22). Aaron, as high priest, bore the sins of Israel (Exodus 28:36-38). Greater still, as its fulfilment, Christ bore the guilt of all that whoever believes in Him might have eternal life (John 3:16; 6:35, 39-40).
The pastor fulfils the role of high priest in a way as well. In Confession and Absolution, the people publicly confess their sins as the pastor stands in the chancel area (functioning as the Holy of Holies), and the pastor then forgives their sins by the stead and command of Christ (John 20:21-23). The same is done in private confession. When a layperson sits in their pastor’s office and confesses his or her sins, the pastor is dutybound to forgive their sins by Christ’s stead and command where there is genuine contrition. When the penitent’s contrition is genuine, the pastor spends no time determining whether their confession is worthy of forgiveness. Furthermore, by his ordination vows, he cannot break the seal of confession by revealing their sins to anybody, for it remains between God and the penitent. When the penitent leaves the pastor’s office, therefore, the pastor leaves the sin before God and has Him deal with it in the life, death, and resurrection of Christ and no longer thinks on the matter.