Venerable Pius XII : Mediator between God and men[1] and High Priest who has gone before us into heaven, Jesus the Son of God,not content, while He dwelt with us on earth, merely to give notice that redemption had begun, and to proclaim the long-awaited Kingdom of God, but gave Himself besides in prayer and sacrifice to the task of saving souls, even to the point of offering Himself, as He hung from the cross, a Victim unspotted unto God, to purify our conscience of dead works, to serve the living God.

MEDIATOR DEI

ENCYCLICAL OF POPE PIUS XII
ON THE SACRED LITURGY
TO THE VENERABLE BRETHREN, THE PATRIARCHS, PRIMATES,
ARCHBISHOPS, BISHIOPS, AND OTHER ORDINARIES
IN PEACE AND COMMUNION WITH THE APOSTOLIC SEE

Venerable Brethren,
Health and Apostolic Benediction.

1. Mediator between God and men[1] and High Priest who has gone before us into heaven, Jesus the Son of God[2] quite clearly had one aim in view when He undertook the mission of mercy which was to endow mankind with the rich blessings of supernatural grace. Sin had disturbed the right relationship between man and his Creator; the Son of God would restore it. The children of Adam were wretched heirs to the infection of original sin; He would bring them back to their heavenly Father, the primal source and final destiny of all things. For this reason He was not content, while He dwelt with us on earth, merely to give notice that redemption had begun, and to proclaim the long-awaited Kingdom of God, but gave Himself besides in prayer and sacrifice to the task of saving souls, even to the point of offering Himself, as He hung from the cross, a Victim unspotted unto God, to purify our conscience of dead works, to serve the living God.[3] Thus happily were all men summoned back from the byways leading them down to ruin and disaster, to be set squarely once again upon the path that leads to God. Thanks to the shedding of the blood of the Immaculate Lamb, now each might set about the personal task of achieving his own sanctification, so rendering to God the glory due to Him.

2. But what is more, the divine Redeemer has so willed it that the priestly life begun with the supplication and sacrifice of His mortal body should continue without intermission down the ages in His Mystical Body which is the Church. That is why He established a visible priesthood to offer everywhere the clean oblation[4] which would enable men from East to West, freed from the shackles of sin, to offer God that unconstrained and voluntary homage which their conscience dictates.

3. In obedience, therefore, to her Founder's behest, the Church prolongs the priestly mission of Jesus Christ mainly by means of the sacred liturgy. She does this in the first place at the altar, where constantly the sacrifice of the cross is represented[5] and with a single difference in the manner of its offering, renewed.[6] She does it next by means of the sacraments, those special channels through which men are made partakers in the supernatural life. She does it, finally, by offering to God, all Good and Great, the daily tribute of her prayer of praise. "What a spectacle for heaven and earth," observes Our predecessor of happy memory, Pius XI, "is not the Church at prayer! For centuries without interruption, from midnight to midnight, the divine psalmody of the inspired canticles is repeated on earth; there is no hour of the day that is not hallowed by its special liturgy; there is no state of human life that has not its part in the thanksgiving, praise, supplication and reparation of this common prayer of the Mystical Body of Christ which is His Church!"[7]