Pastors of souls must therefore realize that, when the liturgy is celebrated, something more is required than the mere observation of the laws governing valid and licit celebration; it is their duty also to ensure that the faithful take part fully aware of what they are doing, actively engaged in the rite, and enriched by its effects. (SC 11)
Therefore no other person, even if he be a priest, may add, remove, or change anything in the liturgy on his own authority. (SC 22, 3)
38. In the course of the Synod, there was frequent insistence on the need to avoid any antithesis between the ars celebrandi, the art of proper celebration, and the full, active and fruitful participation of all the faithful. The primary way to foster the participation of the People of God in the sacred rite is the proper celebration of the rite itself. The ars celebrandi is the best way to ensure their actuosa participatio. The ars celebrandi is the fruit of faithful adherence to the liturgical norms in all their richness; indeed, for two thousand years this way of celebrating has sustained the faith life of all believers, called to take part in the celebration as the People of God, a royal priesthood, a holy nation (cf. 1 Pet 2:4-5, 9).
40. Emphasizing the importance of the ars celebrandi also leads to an appreciation of the value of the liturgical norms. The ars celebrandi should foster a sense of the sacred and the use of outward signs which help to cultivate this sense, such as, for example, the harmony of the rite, the liturgical vestments, the furnishings and the sacred space. The eucharistic celebration is enhanced when priests and liturgical leaders are committed to making known the current liturgical texts and norms, making available the great riches found in the General Instruction of the Roman Missal and the Order of Readings for Mass. Perhaps we take it for granted that our ecclesial communities already know and appreciate these resources, but this is not always the case. These texts contain riches which have preserved and expressed the faith and experience of the People of God over its two-thousand-year history. Equally important for a correct ars celebrandi is an attentiveness to the various kinds of language that the liturgy employs: words and music, gestures and silence, movement, the liturgical colours of the vestments. By its very nature the liturgy operates on different levels of communication which enable it to engage the whole human person. The simplicity of its gestures and the sobriety of its orderly sequence of signs communicate and inspire more than any contrived and inappropriate additions. Attentiveness and fidelity to the specific structure of the rite express both a recognition of the nature of Eucharist as a gift and, on the part of the minister, a docile openness to receiving this ineffable gift.