From Pope St. John Paul II’s Apostolic Exhortation Familiaris Consortio (1981):
Christian marriage normally requires a liturgical celebration expressing in social and community form the essentially ecclesial and sacramental nature of the conjugal covenant between baptized persons.
Inasmuch as it is a sacramental action of sanctification, the celebration of marriage—inserted into the liturgy, which is the summit of the Church’s action and the source of her sanctifying power166—must be per se valid, worthy and fruitful. This opens a wide field for pastoral solicitude, in order that the needs deriving from the nature of the conjugal convent, elevated into a sacrament, may be fully met, and also in order that the Church’s discipline regarding free consent, impediments, the canonical form and the actual rite of the celebration may be faithfully observed. The celebration should be simple and dignified, according to the norms of the competent authorities of the Church. It is also for them—in accordance with concrete circumstances of time and place and in conformity with the norms issued by the Apostolic See167—to include in the liturgical celebration such elements proper to each culture which serve to express more clearly the profound human and religious significance of the marriage contract, provided that such elements contain nothing that is not in harmony with Christian faith and morality.
Inasmuch as it is a sign, the liturgical celebration should be conducted in such a way as to constitute, also in its external reality, a proclamation of the word of God and a profession of faith on the part of the community of believers. Pastoral commitment will be expressed here through the intelligent and careful preparation of the Liturgy of the Word and through the education to faith of those participating in the celebration and in the first place the couple being married.
Inasmuch as it is a sacramental action of the Church, the liturgical celebration of marriage should involve the Christian community, with the full, active and responsible participation of all those present, according to the place and task of each individual: the bride and bridegroom, the priest, the witnesses, the relatives, the friends, the other members of the faithful, all of them members of an assembly that manifests and lives the mystery of Christ and His Church. For the celebration of Christian marriage in the sphere of ancestral cultures or traditions, the principles laid down above should be followed.
166 Sacrosanctum Concilium, 10.
167 Cf. Ordo celebrandi matrimonium, 17.
— Familiaris Consortio 67