Every high priest is selected from among the people and is appointed to represent the people in matters related to God, to offer gifts and sacrifices for sins. – Hebrews 5:1
High priests were important. They were the mediators between God and man. Only the Levites (from the tribe of Levi) were chosen by God to become high priests. High priests were people with the same nature as you and me. This is why they first had to offer a sacrifice for themselves before they could offer sacrifice for others.
Only the Levites were allowed to offer in the tabernacle. It was not because they were holier or more devoted, but because God had arranged it that way. When a high priest died, another replaced him. This happened until Jesus Christ came.
The eternal high priest
Jesus Christ is the only High Priest who did not come and leave; He is the eternal High Priest.
Hebrews 9:11-12 says: ‘But when Christ came as high priest… He went through the greater and more perfect tabernacle that is not made with human hands, that is to say, is not a part of this creation. He did not enter by means of the blood of goats and calves; but He entered the Most Holy Place once for all by His own blood, thus obtaining eternal redemption.’
This means that Jesus does not need a successor and does not have to offer a sacrifice again. Hebrews 10:14 says that through that one sacrifice, Jesus forever made perfect those who are being made holy.
Jesus did not first have to sacrifice for Himself, because He is perfect, pure and holy. Jesus is the eternal High Priest. All images and symbols, including the other sacrifices, did not have any value anymore when Jesus came. Now every child of God is able to approach God as a priest in the name of Jesus. He is the way (to God), the truth and the life.
In 1 Peter 2:9 it says: ‘But you are a chosen people, a royal priesthood, a holy nation, God’s special possession, that you may declare the praises of Him who called you out of darkness into His wonderful light.’