Irenaeus of Lyons · a new plain-English translation from the original language
Christ did not come into what was alien to him, but visited us with his own grace; and he made our flesh capable of receiving salvation, truly shedding his blood for us, and truly presenting to us his own flesh in the Eucharist.
Empty, too, are those who say that God entered into what belonged to another, as though he coveted what was not his, so as to present to God, as man, one made by another — one he himself had neither made nor formed, and who indeed had, from the outset, been forsaken by his own proper Maker of men. His coming, then, on their account, into what belonged to another, was not just; nor did he truly ransom us by his blood, if he did not truly become man, restoring to his own formed creature what had been proclaimed at the outset — that man was fashioned to resemble and mirror God's own likeness — not deceitfully snatching what belonged to another, but justly and generously taking up what was his own: justly, insofar as it concerns the apostasy, ransoming us from it by his own blood; generously, insofar as it concerns us who have been ransomed. For we had given him nothing beforehand, nor does he crave anything from us, as though he were lacking; rather it is we who lack that fellowship which comes from him. And for this reason he poured out himself. Such people, then, hold in contempt the entire dispensation of God, and deny the flesh's salvation, and reject its renewal, claiming it incapable of incorruptibility. But if this flesh is not to be saved, then the Lord did not ransom us by his blood, nor is the Eucharist's cup the fellowship of his blood, nor is the bread we break the fellowship of his body. For blood comes only from veins and flesh, and from the remaining elements belonging to man's substance — which the Word of God truly became, and by his own blood ransomed us. As his own Apostle likewise puts it: "In him our ransom is secured by his blood, and with it the release of our sins."
And since we are his members, and are nourished by the creation — and it is he himself who supplies the creation to us, making his sun rise and sending rain as he wills — he has confirmed as his own blood that cup which is a creature, the cup which was poured out, from which he increases our blood; and as his own body that bread which is from the creation, from which he increases our bodies. When, therefore, the mixed cup and the bread that has been made receive the Word of God and become the Eucharist of the blood and body of Christ, and from these the substance of our flesh is increased and made to stand — how can they say that the flesh is incapable of the gift of God, which is eternal life, when it is nourished by the blood and body of Christ, and is his member? As the blessed Apostle says in the Epistle to the Ephesians: For we belong to his body, formed from his flesh and drawn from his bones — the Apostle is not here describing some intangible and unseen being (since a spirit possesses neither bone nor flesh), but rather that genuine bodily frame composed of flesh and tendon and bone, sustained by the cup that is his blood and built up by the loaf that is his body.
And just as a shoot cut from the vine, set into the soil, yields fruit at the proper season, and a kernel of wheat, cast into the earth and broken down, springs up manifold through the Spirit of God who upholds all things — these elements, then, by wisdom pass into the service of man, and once they take on the word of God become the thanksgiving-offering, that is, Christ's blood and flesh — so likewise our bodies, fed by this, laid in the ground, and there dissolved, will be raised again at their appointed hour, the divine Word conferring on them a rising to the honor of God the Father, who arrays the mortal in immortality and freely grants incorruption to that which decays, since God's strength comes to fullness amid frailty. This is so that we should not, as though we possessed life from ourselves, ever grow inflated and set ourselves up against God, taking on a thankless disposition; but instead, discovering through experience that endurance unto eternity comes from his greatness and not from anything native to us, we should never be defrauded of the glory that truly belongs to God, nor stay uninformed about our own condition; but rather that we should recognize both what God is capable of and what benefit accrues to man, and never depart from a true grasp of the things that exist, and of their manner of existing — namely, of God and of man. And is it not perhaps, as we said before, for this reason that God allowed the dissolution to take place in us — that, being instructed in every respect, we might be careful in all things, ignorant neither of God nor of ourselves? In the frailty of the flesh God's might and splendor are displayed openly, since he will render our body, which he shaped from the clay of the ground, a sharer in rising again and in immortality, and will grant it enjoyment of life without end — he who gives even this brief, ordinary life we now have.