In John chapter seventeen, Jesus prays for Himself, then prays for His disciples, then for all believers. As High Priest, one of the first responsibilities given to Aaron by God is that they are to bear the iniquities associated with their priesthood and their family line. Then they are to bear the iniquities related to the Sanctuary, offering sacrifice for those they are responsible to. Jesus was given the ultimate authority, and with that came the ultimate accountability to the disciples God entrusted to Him and to all believers. As High Priest, they are responsible for the people they serve: having something to give as Sacrifice for their own sins and sacrificing what the people bring as offerings to the Lord. Jesus, who was sinless, brought all he had, Himself (His love), to the altar to be sacrificed, for everyone's sin. This was God's plan for humanity because it is said it "pleased the Lord the crush Him." (Isaiah 53:10)
The priesthood changed from the descendants of Aaron, which had become corrupted over time through disobedience, to be restored in the line of Melchizedek. He was king of Salam and priest of the highest God. He was “without father, without mother, without genealogy, having neither beginning of days nor end of life, but made like the Son of God, remains a priest continually.” (Heb 7:3) In the likeness of Melchizedek there will arise another priest, the one who came to be the fulfillment of the law. No earthly priest could take away sin the way Jesus did. Therefore, Jesus is far better than the ministry of the priesthood under the Law of Moses. He is better than Moses.
Jesus will continue forever as our high priest. He who became a sin offering for all of us was crucified, stormed the gates of hades and rose again triumphantly, and now sits on the right side of God. Jesus is God, and He continues forever. He is unchangeable, so His priesthood is unchangeable. Therefore, He can save those who come to God through Him since He now lives in us, in the form of the Holy Spirit, and makes intercession for us.
What does this mean for us? It means that “our righteousness must exceed that of the Pharisees.” (Matt:520) We can have no compromise in our walk as Christians. We must follow all the laws set right through Jesus to enter His kingdom; anything less will not be enough. What Jesus offered us through His Sacrifice was salvation by paying for our sins. Salvation is free, but it will cost us the world. What Jesus is saying is essentially that 99% of obedience is disobedience. Jesus is firm in this when He says, “For assuredly, I say to you, till heaven and earth pass away, one jot or one tittle will by no means pass from the law till all is fulfilled.” (Matt 5:18) To be called great in the kingdom of heaven, we need to live and teach full obedience to the world.