[The Communion] hymn is prayer, the corporate thanksgiving prayer of the members of Christ’s Body, united with one another. Over and over again the prayers of the liturgy and the norms of the General Instruction emphasize this fundamental concept of the unity of the baptized, stressing that when we come together to participate in the Eucharistic celebration we come, not as individuals, but as united members of Christ’s Body. In each of the Eucharistic Prayers, though the petition is worded in slightly different ways, God is asked to send his Holy Spirit to make us one body, one spirit in Christ; the General Instruction admonishes the faithful that “they are to form one body, whether in hearing the Word of God, or in taking part in the prayers and in the singing…” (no. 96). It describes one of the purposes of the opening song of the Mass as to “foster the unity of those who have been gathered” (no. 47), and says of the Communion Chant that “its purpose [is] to express the spiritual union of the communicants by means of the unity of their voices, to show gladness of heart, and to bring out more clearly the ‘communitarian’ character of the procession to receive the Eucharist” (no. 86).
It is difficult for some of us to embrace this emphasis on Mass as the action of a community rather than an individual act of my own faith and piety, but it is important that we make every effort to do so. Christ himself at the Last Supper pleaded with his Father: “Holy Father, keep them in your name that you have given me, so that they may be one just as we are… as you, Father, are in me and I in you, that they also may be in us…” (John 17:11, 21).Baptism has joined us to Christ and to one another as the vine and its branches. The life of Christ, the Holy Spirit, animates each of us individually, and all of us corporately and guides us together in our efforts to become one in Christ.
USCCB The Reception of Holy Communion at Mass