'Jesus has become the guarantor of a better covenant. Now there have been many of those priests, since death prevented them from continuing in office; but because Jesus lives for ever, he has a permanent priesthood. Therefore he is able to save completely those who come to God through him, because he always lives to intercede for them.' (Hebrews 7.22-25, NIV)
As our High Priest, Christ is our Advocate, the mediator between us and God. He looks after our interests and intercedes for us with God. The Old Testament high priest entered the presence of God once a year to plead for the forgiveness of the nation's sins; whereas Christ makes perpetual intercession before God for us. Christ's continuous presence in Heaven with the Father assures us that our sins have been paid for and forgiven. This wonderful assurance frees us from guilt and fear.
Because Jesus died once for all, He brought the sacrificial system to an end. He forgave sins - past, present and future. Jesus is the perfect sacrifice for the forgiveness of sin.
Chapter 7 begins however, with Melchizedek, a priest of God. He is said to remain a priest forever, because his priesthood has no record of beginning or ending. He was a priest of God in Salem (Jerusalem) long before the nation of Israel and the regular priesthood began.
This Melchizedek was king of Salem and priest of God Most High. He met Abraham returning from the defeat of the kings and blessed him, and Abraham gave him a tenth of everything. First, the name Melchizedek means ‘king of righteousness’; then also, ‘king of Salem’ means ‘king of peace’. Without father or mother, without genealogy, without beginning of days or end of life, resembling the Son of God, he remains a priest for ever. (Hebrews 7:1-3, NIV)
Jesus’ high-priestly role was superior to that of any priest of Levi, because the Messiah was a priest of a higher order. If the Jewish priests and their laws had been able to save people, why would God need to send Christ as a priest, who came not from the tribe of Levi (the priestly tribe) but from the tribe of Judah? The animal sacrifices had to be repeated, as they provided only temporary forgiveness; but Christ’s sacrifice was offered once, and it gives total and permanent forgiveness. Because Christ is our High Priest, no minister, priest, leader, or friend, can substitute for Christ’s work and for His role in our salvation.