"A priest clothed in sacred vestments occupies the place of Christ, that he may humbly intercede with God for himself and for all men. (Heb.5:3; 7:27) He wears the sign of the Cross both before and behind him, that he may be ever mindful of His Lord's Passion. He wears the Cross before him on his chasuble, that he may diligently observe the footsteps of Christ, and earnestly study to follow them. (I Pet.2:21) His shoulders also are signed with the Cross, that he may in mercy and for the love of God bear every injury done him by others. He wears the Cross before him, that he may grieve for his own sins ; behind him, that he may compassionately lament the sins of others, ever mindful that he is appointed a mediator between God and the sinner, and that he may not cease from prayer and the Holy Sacrifice until he deserve to win grace and mercy."
~ Thomas A. Kempis