The priest's mission is to be a mediator, a bridge that unites and can lead humanity to God. Only in Christ is mediation fully realized. The priest must belong to God, stand with God, and be completely human. True humanity means truly sharing in human suffering—being a man of compassion.
That means standing at the heart of human passion, concretely bearing with others their suffering and the temptations of our time: "God, where are you in this world?" This is how priesthood is realized, the mediator's function: by carrying within oneself the suffering and passion of the world, transforming it into a cry toward God, laying it before God's eyes and in God's hands, and truly bringing it to the moment of Redemption. Our priesthood is not limited to the act of worship, to the Mass, in which everything is placed in Christ's hands. But all our compassion toward the suffering of a world so far from God is equally a priestly act, an offering.
from the letter of Benedict XVI to priests, Rome, March 2, 2010