A: The Second Vatican Council’s Constitution on the Sacred Liturgy put forward as one of its reforming norms, “That more perfect form of participation in the Mass whereby the faithful, after the priest’s communion, receive the Lord’s body from the same sacrifice, is strongly commended” (55). The postconciliar Missal, incorporating this norm, directs in the General Instruction of the Roman Missal (GIRM): “It is most desirable that the faithful, just as the Priest himself is bound to do, receive the Lord’s Body from hosts consecrated at the same Mass…” (GIRM, 85).
Not only do these documents promote the practice of communion from the altar, but they also ground their prescription in the principle of active participation. Echoing Pope Pius X (patron saint of First Communicants), the Constitution on the Sacred Liturgy says, “In the restoration and promotion of the sacred liturgy, this full and active participation by all the people is the aim to be considered before all else” (14; emphasis added). Hence, the faithful’s communion from the altar ought to be read as a means to their active participation. The GIRM makes the connection more explicit: by means of communicating with hosts consecrated at the same Mass, “Communion may stand out more clearly as a participation in the sacrifice actually being celebrated” (85). In short, the worthy reception of holy communion from the altar, more so than with hosts retrieved from the tabernacle, facilitates the laity’s active participation in the sacrifice of Christ made present during the Mass.
During the Eucharistic Prayer, the lay faithful, in virtue of their baptism, have (or are supposed to have) joined their prayers, works, joys, and sufferings—their entire selves—to Christ as he gives himself to the Father through the hands of the priest by the power of the Holy Spirit. They have, in other words, actively participated in the offering of themselves and of Christ—the pinnacle of liturgical participation. The fruit of this sacrificial participation, as well as the most explicit connection to it, is the sacramental reception of the body and blood of Christ.
Since the laity have participated in offering the sacrifice of the Mass, it is reasonable that they also receive that same sacrifice from the altar upon which it was offered. Certainly, one does not receive less of Christ from the tabernacle. And as a matter of practicality, especially at Mass with large numbers, communion from the tabernacle may be necessary. But all things being equal, the Roman Missal desires the that the people receive the same sacrifice that they themselves offered.