Eternal Priesthood

Hebrews 7:20-25

The author is continuing his sermon on Psalm 110:4, exploring the Melchizedek priestly order that Jesus has become high priest in. The author now focuses on the oath that God made to this priestly line, and to the Messiah in particular, and the new covenant that Jesus brings in as the high priest in the order of Melchizedek. This goes back to the author's main point: the supremacy of Christ and of the new covenant.
He argues his point by contrasting the Melchizedek priestly order with the Levitical order: First, God has guaranteed that the Melchizedek order would be eternal, and that the Messiah would be the eternal high priest, by an oath; he has never made that guarantee to the Levitical order. Therefore, the priesthood of Jesus rests securely on God's promise and oath and is therefore superior to the Levitical priesthood. Second, the Levitical priests were mortal and therefore there were a lot of them; Jesus' priesthood is eternal because Jesus lives forever. Therefore, the priesthood of Jesus is superior because it lasts forever. This means that the covenant that we have under the priesthood of Christ is also superior in that it rests on God's oath, lasts as long as Jesus is high priest (forever!) and, therefore, we are offered a complete salvation (contrasted to the "partial" salvation available under the law).
My salvation rests in Christ's ability to intercede on my behalf. Because he is always alive, he is always able to point to his blood that was the payment for all my sins. When I ask for forgiveness, Christ, as high priest, takes that request to his Father, pointing to his shed blood which demands that God forgive my sin because Jesus has already paid for it and it would be unjust for God to demand two payments. What an incredible plan God has brought! What a great salvation has been purchased on my behalf! There is no reason to fear that God's mercy will ever run out because my forgiveness depends as much on his justice as it does his mercy. Jesus sacrifice completely and forever satisfies the justice of God and I am saved for all time in all areas of my life. Thank-you for saving me! What can I say?