On January 25, 1964, Paul VI issued a Motu Proprio, Sacram Liturgiam, on putting into effect some of the prescriptions found in the Constitution on the Liturgy, promulgated at the end of the previous year.
That the sacred liturgy be carefully safeguarded, developed, and, where necessary, reformed has been the concern of earlier popes, of ourself, and of the bishops of the Church. The many published documents on liturgical topics, known to all, confirm this. So does the Constitution on the Liturgy, approved with near unanimity by Vatican Council II in solemn session and promulgated 4 December 1963.
The concern for the liturgy rests on the fact that “in the earthly liturgy we take part in a foretaste of that heavenly liturgy celebrated in the holy city of Jerusalem toward which we journey as pilgrims, where Christ is sitting at the right hand of God, a minister of the holies and of the true tabernacle (cf. Rev 21:2; Col 3:1; Heb 8:2); we sing a hymn to the Lord’s glory with the whole company of heaven, venerating the memory of the saints, we hope for some part and communion with them; we eagerly await the Savior, our Lord Jesus Christ, until he, our life, shall appear and we too will appear with him in glory (cf Phil 3:20; Col 3:2).”
The hearts of the faithful who so worship God, the source and exemplar of all holiness, are therefore drawn, even compelled, to seek this holiness and in this way to become in this earthly pilgrimage “seekers of holy Zion.”
Accordingly, our foremost concern is clearly that the faithful, and especially priests, dedicate themselves first of all to the study of the Constitution on the Liturgy and from this moment on prepare themselves to carry out its prescriptions wholeheartedly as soon as these take effect. Because by the very nature of the case the understanding and dissemination of liturgical laws must go into effect without delay, we earnestly exhort bishops of dioceses to an immediate, intense effort, aided by their sacred ministers, “the stewards of God’s mysteries,” so that their own faithful, in keeping with their age, particular state in life, and level of culture will grasp the innate power and value of the liturgy and at the same time participate devoutly, body and soul, in the rites of the Church.