The Mystery of the Eucharist (Holy Communion) is the third of the Mysteries of Christian initiation. In the Eucharist the newly baptized, who was born in Christ and filled with the Holy Spirit, receives the communion of the Body and Blood of Christ at the holy Eucharistic table. But unlike Baptism and Chrismation, which we receive only once, we receive the Mystery of the Eucharist throughout our lives, since it is through this Mystery that we grow in the grace received in Baptism and Chrismation—the grace to be sons and daughters of God.
For this reason our Church offers Communion to the newly baptized.
432 In the Mystery of Holy Communion, Christ gives us his very self, his Body and Blood, as nourishment for our growth in the new life. At the Mystical Supper (Last Supper) Christ offered himself for us so that we might be able to offer our lives for our neighbour, as he offered his life (see Jn 13:34). Receiving Communion in the Lord’s Body and Blood, we receive a pledge of life eternal: “Those who eat my flesh and drink my blood have eternal life, and I will raise them up on the last day” (Jn 6:54). Partaking of the Body and Blood of Christ, we already have eternal life, the fullness of which will be revealed in the glorious second coming of Christ. “For since he bestowed on us his own image and his own spirit and we did not guard them, he took himself a share in our poor and weak nature, in order that he might cleanse us and make us incorruptible, and establish us once more as partakers of his divinity.”
The Holy Eucharist most fully manifests and creates our communion both with God and with others. All who have communion with Christ become “one body in Christ, and individually we are members one of another” (Rom 12:5). In other words, we become one Church. “Because there is one [Eucharistic] bread, we who are many are one body [of Christ], for we all partake of the one bread” (1 Cor 10:17). We profess this same truth in the Anaphora of Saint Basil the Great when we ask God to “unite all of us who share in this one bread and cup with one another into the communion of the one Holy Spirit.” Saint John of Damascus teaches:
Participation is spoken of; for through it we partake of the divinity of Jesus. Communion, too, is spoken of, and it is an actual communion, because through it we have communion with Christ and share in his flesh and his divinity: [at same time] we have communion and are united with one another through it. For since we partake of one bread, we all become one body of Christ and one blood, and members one of another, being of one body with Christ.