Pope Paul VI - Missale Romanum - Promulgation of the Roman Missal Revised by Decree of the Second Vatican Ecumentical Council - 3 April 1969
It must be acknowledged that the chief innovation in the reform concerns the eucharistic prayer. Although the Roman Rite over the centuries allowed for a multiplicity of different texts in the first part of the prayer (the preface), the second part, called the Canon actionis, took on a fixed form during the period of the fourth and fifth centuries. The Eastern liturgies, on the other hand, allowed a degree of variety into the anaphoras themselves. On this point, first of all, the eucharistic prayer has been enriched with a great number of prefaces-drawn from the early tradition of the Roman Church or recently composed-in order that the different facets of the mystery of salvation will stand out more clearly and that there will be more and richer themes of thanksgiving. But besides this, we have decided to add three new canons to the eucharistic prayer. Both for pastoral reasons, however, and for the facilitation of concelebration, we have ordered that the words of the Lord be identical in each form of the canon. Thus in each eucharistic prayer we wish those words to be as follows: over the bread: Accipite et manducate ex hoc omnes: Hoc est enim Corpus meum, quod pro vobis tradetur; over the chalice: Accipite et bibite ex eo omnes: Hic est enim calix Sanguinis mei novi et aeterni testamenti, qui pro vobis et pro multis effundetur in remissionem peccatorum. Hoc facite in meam commemorationem. The words Mysterium fidei have been removed from the context of Christ's own words and are spoken by the priest as an introduction to the faithful's acclamation.
In the Order of Mass the rites have been "simplified, due care being taken to preserve their substance."[8] "Elements that, with the passage of time, came to be duplicated or were added with but little advantage"[9] have been eliminated, especially in the rites for the presentation of the bread and wine, the breaking of the bread, and communion.
Also, "other elements that have suffered injury through accident of history" are restored "to the tradition of the Fathers,"[10] for example, the homily,[11] the general intercessions or prayer of the faithful,[12] and the penitential rite or act of reconciliation with God and the community at the beginning of the Mass, which thus, as is right, regains its proper importance.
According to the decree of the Second Vatican Council, that "a more representative portion of the holy Scriptures be read to the people over the course of a prescribed number of years,"[13] the Sunday readings are arranged in a cycle of three years. In addition, on Sundays and all the major feasts the epistle and gospel are preceded by an Old Testament reading or, at Easter, by readings from Acts. This is meant to provide a fuller exposition of the continuing process of the mystery of salvation, as shown in the words of divine revelation. These broadly selected biblical readings, which set before the faithful on Sundays and holydays the most important part of sacred Scripture, are complemented by other parts of the Bible read on other days.