And He took bread, gave thanks and broke it, and gave it to them, saying, “This is My body which is given for you; do this in remembrance of Me.” Likewise He also took the cup after supper, saying, “This cup is the new covenant in My blood, which is shed for you. (Luke 22:19-20)
For we offer to him his own, fittingly proclaiming the communion and union of the flesh and the Spirit. For just as the bread from the earth, when it has received the invocation of God, is no longer ordinary bread, but eucharist, consisting of two things, earthly and heavenly, so also our bodies, receiving the eucharist, are no longer corruptible, having the hope of the resurrection. (Irenaeus)
[In the Liturgy, the celebrant says: “Your own of Your own, we offer unto you on behalf of all and for all,” which reflects Irenaeus’ thought that we offer to Christ His own Body and Blood which aren’t merely human but that of the God-man. That which we offer to the congregants in Communion is not merely physical and corruptible for it is also heavenly and eternal. In the Eucharist we experience God and humanity, heaven and earth united in God’s plan of salvation.]
Just as the wood of the vine, planted in the earth, bore fruit in its own time, and the grain of wheat, falling into the earth and being decomposed, was raised up manifold by the Spirit of God who sustains all, then, by wisdom, they come to the use of men, and receiving the Word of God, become eucharist, which is the body and blood of Christ; in the same way, our bodies, nourished by it, having been placed in the earth and decomposing in it, shall rise in their time, when the Word of God bestows on them the resurrection to the glory of God the Father, who secures immortality for the mortal and bountifully bestows incorruptibility on the corruptible [cf. 1 Cor 15:53], because the power of God is made perfect in weakness [cf. 2 Cor 12:9], that we may never become puffed up, as if we had life from ourselves, nor exalted against God, entertaining ungrateful thoughts, but learning by experience that it is from his excellence, and not from our own nature, that we have eternal continuance, that we should neither undervalue the true glory of God nor be ignorant of our own nature, but should know what God can do and what benefits man, and that we should never mistake the true understanding of things as they are, that is, of God and of man. (Irenaeus) . . .
[Behr concludes with is own thoughts: ]
It is by receiving the Eucharist, as the wheat and the vine received the fecundity of the Spirit, that Christians are prepared, as they also make the fruits into the bread and wine, for their own resurrection effected by the Word, at which point, just as the bread and wine received the Word and so become the body and blood of Christ, the eucharist, so also will their bodies receive immortality and incorruptibility from the Father. Christians themselves, therefore, need to use the fruits of the world eucharistically, for it is by these that they are prepared for the resurrection and the gift of incorruptibility. (ASCETICISM AND ANTHROPOLOGY IN IRENEAUS AND CLEMENT, pp 71-73)
The bread and wine of the Eucharist are transformed by the Word and Spirit, uniting Creator to creation. So too, those receiving Communion are transformed by receiving the same Word and Spirit into their lives, into their bodies, hearts, souls and minds and in so doing are united to divinity.