All works of the Priesthood were laid out as a type of the High Priest to come. We see that a reality of the rituals of the priesthood involved refreshing the atonement and purification of a sinful and insufficient servant. What we see in the fulfillment that is Christ is the "once-for-all" ministry of a pure and sinless High Priest [Cross Reference - Hebrews 7:1-10:25].