3. The Other Parts of the Mass
[57.] It is the right of the community of Christ’s faithful that especially in the Sunday celebration there should customarily be true and suitable sacred music, and that there should always be an altar, vestments and sacred linens that are dignified, proper, and clean, in accordance with the norms.
[58.] All of Christ’s faithful likewise have the right to a celebration of the Eucharist that has been so carefully prepared in all its parts that the word of God is properly and efficaciously proclaimed and explained in it; that the faculty for selecting the liturgical texts and rites is carried out with care according to the norms; and that their faith is duly safeguarded and nourished by the words that are sung in the celebration of the Liturgy.
[59.] The reprobated practice by which Priests, Deacons or the faithful here and there alter or vary at will the texts of the Sacred Liturgy that they are charged to pronounce, must cease. For in doing thus, they render the celebration of the Sacred Liturgy unstable, and not infrequently distort the authentic meaning of the Liturgy.
[60.] In the celebration of Mass, the Liturgy of the Word and the Liturgy of the Eucharist are intimately connected to one another, and form one single act of worship. For this reason it is not licit to separate one of these parts from the other and celebrate them at different times or places. Nor is it licit to carry out the individual parts of Holy Mass at different times of the same day.
[61.] In selecting the biblical readings for proclamation in the celebration of Mass, the norms found in the liturgical books are to be followed, so that indeed “a richer table of the word of God will be prepared for the faithful, and the biblical treasures opened up for them”.
[62.] It is also illicit to omit or to substitute the prescribed biblical readings on one’s own initiative, and especially “to substitute other, non-biblical texts for the readings and responsorial Psalm, which contain the word of God”.
[63.] “Within the celebration of the Sacred Liturgy, the reading of the Gospel, which is “the high point of the Liturgy of the Word”, is reserved by the Church’s tradition to an ordained minister. Thus it is not permitted for a layperson, even a religious, to proclaim the Gospel reading in the celebration of Holy Mass, nor in other cases in which the norms do not explicitly permit it.