Jesus is the high priest of a new order. The Levitical priesthood of the Old Testament was responsible for the sacrifices and maintenance of the temple. Without the Levitical priesthood, sacrifices would go unmade, the incense would never be lit, and the showbread would never be put out. Your average farmer or business person couldn't make their own sacrifices, the priests could only make sacrifices. Now, in Jesus, He has made us our own priests, we need no mediator between us and God.