A caution against the urge to interpret Catholic liturgy as solely a Congregationalist enterprise:
39. Furthermore, given the very nature of ecclesial communion and its relation to the sacrament of the Eucharist, it must be recalled that “the Eucharistic Sacrifice, while always offered in a particular community, is never a celebration of that community alone. In fact, the community, in receiving the Eucharistic presence of the Lord, receives the entire gift of salvation and shows, even in its lasting visible particular form, that it is the image and true presence of the one, holy, catholic and apostolic Church”. (CDF, Letter to the Bishops of the Catholic Church on Some Aspects of the Church Understood as Communion Communionis Notio (28 May 1992), 11: AAS 85 (1993), 844.) From this it follows that a truly Eucharistic community cannot be closed in upon itself, as though it were somehow self-sufficient; rather it must persevere in harmony with every other Catholic community.
One apt matter for discussion is the effect on divisions within the Catholic Church on the Eucharist, and vice versa. We might discern a spectrum between liturgical reforms moving too far and those opposing reform being too resistant. Is there a path of “harmony” through the modern situation? Many people entrenched on one side or the other acknowledge a certain lament over the divisions.
The ecclesial communion of the Eucharistic assembly is a communion with its own Bishop and with the Roman Pontiff. The Bishop, in effect, is the visible principle and the foundation of unity within his particular Church. (Cf. Lumen Gentium, 23.) It would therefore be a great contradiction if the sacrament par excellence of the Church’s unity were celebrated without true communion with the Bishop. As Saint Ignatius of Antioch wrote: “That Eucharist which is celebrated under the Bishop, or under one to whom the Bishop has given this charge, may be considered certain”. (Ad Smyrnaeos, 8: PG 5, 713.) Likewise, since “the Roman Pontiff, as the successor of Peter, is the perpetual and visible source and foundation of the unity of the Bishops and of the multitude of the faithful”, (Lumen Gentium, 23.) communion with him is intrinsically required for the celebration of the Eucharistic Sacrifice. Hence the great truth expressed which the Liturgy expresses in a variety of ways: “Every celebration of the Eucharist is performed in union not only with the proper Bishop, but also with the Pope, with the episcopal order, with all the clergy, and with the entire people. Every valid celebration of the Eucharist expresses this universal communion with Peter and with the whole Church, or objectively calls for it, as in the case of the Christian Churches separated from Rome”. (CDF, Letter to the Bishops of the Catholic Church on Some Aspects of the Church Understood as Communion Communionis Notio (28 May 1992), 14: AAS 85 (1993), 847.)
And we wrap up with the role of the bishops and pope, including a bit of Roman theological wiggle room for our Orthodox brothers and sisters, who are not in union with “peter,” in the sense of the Bishop of Rome. But certainly they would acknowledge the apostolic roots of Peter in the Church.
If you want to reference that letter from the CDF and Cardinal Ratzinger, it is here.