Pope Paul VI
Sacerdotalis Caelibatus §19
Sacerdotalis Caelibatus: On the Celibacy of the Priest
19 The Christian priesthood, being of a new order, can be understood only in the light of the newness of Christ, the Supreme Pontiff and eternal Priest, who instituted the priesthood of the ministry as a real participation in His own unique priesthood. (15) The minister of Christ and dispenser of the mysteries of God, (16) therefore, looks up to Him directly as his model and supreme ideal. (l7) The Lord Jesus, the only Son of God, was sent by the Father into the world and He became man, in order that humanity which was subject to sin and death might be reborn, and through this new birth (18) might enter the kingdom of heaven. Being entirely consecrated to the will of the Father, (19) Jesus brought forth this new creation by means of His Paschal mystery; (20) thus, He introduced into time and into the world a new form of life which is sublime and divine and which radically transforms the human condition. (21)
Source: Sacerdotalis Caelibatus (Vatican.va)