But since the human being is twofold, blended together from soul and body, those who are being saved must necessarily lay hold through both of the One who leads toward life. Therefore the soul, blended with Him through faith, has from this the beginnings of salvation; for union with life brings participation in life. The body, however, comes to participate in and be blended with the One who saves in another way.
For just as those who have taken poison through treachery extinguish its destructive power by another medicine, and the antidote must enter the human inward parts in a manner corresponding to the deadly substance so that through them the power of the remedy may be distributed throughout the whole body, so we, after tasting what dissolves our nature, necessarily came to need what gathers together what had been dissolved. In this way such an antidote, once within us, might by its own contrary action drive out the harm previously introduced into the body by the poison.
What, then, is this? Nothing other than that body which was shown to be stronger than death and inaugurated life for us. For just as a little leaven, as the Apostle says, makes the whole lump like itself, so the body made immortal by God, once it is in ours, transforms and changes the whole into itself. For just as, when something destructive is mixed with something wholesome, the whole mixture is spoiled along with it, so too the immortal body, once it is in the one who receives it, transforms the whole into its own nature.
But nothing can enter within the body in any other way than by being mixed with the inward parts through eating and drinking. Therefore the body must receive the life-giving power in the way that is possible for its nature.
Since that God-bearing body alone received this grace, and since it has been shown that our body cannot become immortal in any other way unless, through fellowship with the immortal, it comes to participate in incorruption, we must consider how it became possible for that one body, forever distributed among so many countless believers throughout the whole inhabited world, to become whole in each person through the portion and yet itself remain whole.
Therefore, so that our faith, looking to what follows logically, may have no doubt about the question before us, the discussion should turn briefly to the physiology of the body.
For who does not know that the nature of our body, taken by itself, does not possess life in some independent subsistence of its own, but holds itself together and remains in being through a power that flows into it, continually drawing to itself what is lacking and casting off what is excessive? It is like a leather vessel filled with liquid: if what is inside drains out through the bottom, it will not preserve its full shape unless something else enters from above in place of what is emptied. Thus anyone who sees the swollen form of such a vessel knows that the shape does not belong to the visible vessel by itself; rather, what flows into it and comes to be within it gives shape to the container. So too the structure of our body has nothing known to us that belongs to it by itself and sustains its constitution; it remains in being through a power supplied to it.
This power both is and is called nourishment. Yet it is not the same for every body that is nourished; rather, the One who orders nature has allotted to each what is suitable for it. Some animals feed by digging up roots; for others grass is food; for some, flesh. For human beings, however, bread is the principal food. And for the maintenance and preservation of the body's moisture there is drink—not water alone, but often water made pleasant with wine—to assist the heat within us.
Anyone who looks at these things is therefore, in potentiality, looking at the bulk of our body. For when they come to be in me, they become blood and body, as nourishment is appropriately changed by the transforming power into the form of the body. Having clarified these things in this way, we must return our thought to the question before us. For the question was how that one body of Christ gives life to the whole of human nature in all those in whom faith is present, being distributed to all and yet itself not diminished.
Perhaps, then, we are coming near a plausible account.
If the subsistence of every body comes from nourishment, and nourishment consists of food and drink; if in food there is bread, and in drink water made pleasant with wine; and if the Word of God, as was explained earlier, being both God and Word, was blended with human nature and, when He came to be in a body like ours, did not introduce any novel bodily constitution into human nature but gave His own body continuance through the customary and appropriate means, maintaining its subsistence by food and drink—and the food was bread—then the following holds. Just as with us, as has already been said many times, someone who sees bread in a certain sense sees the human body, because when the bread comes to be within it, the bread becomes the body, so there too the God-bearing body, having received bread as nourishment, was in a certain sense the same as it, since the nourishment, as has been said, was changed into the nature of the body. For what belongs to all flesh was acknowledged of that flesh as well: that body too was sustained by bread. But the body, through the indwelling of God the Word, was transformed to divine dignity.
Therefore we rightly believe that now also the bread sanctified by the Word of God is transformed into the body of God the Word. For that body too was bread in potentiality, and it was sanctified by the indwelling of the Word who tabernacled in the flesh. Therefore, just as the bread transformed in that body passed into divine power, through the same cause the same thing happens now.
For there the grace of the Word made holy the body whose constitution came from bread and which, in a certain way, was itself bread. Here likewise the bread, as the Apostle says, 'is sanctified through the word of God and prayer'; it does not become the body of the Word by passing through the process of eating, but is immediately transformed into the body through the Word, as the Word Himself said: 'This is My body.'
And since all flesh is also nourished through moisture—for without conjunction with it the earthy element in us would not remain alive—just as we support the solid part of the body through firm and resistant food, so in the same way we supply the moist part from a nature of the same kind. When this comes to be within us, the transforming power turns it into blood, especially if through wine it receives the capacity to be transformed into heat.
Since that God-bearing flesh also received this part for its own constitution, and since the God who was manifested mixed Himself with perishable nature for this very purpose—that through communion with divinity humanity might also be deified—for this reason, by the dispensation of grace, He sows Himself into all who have believed through the flesh whose constitution is from wine and bread, blending Himself with the bodies of believers, so that through union with the immortal the human being too may become a participant in incorruption.
He grants these things by the power of the blessing, transforming the nature of the visible things into that immortal reality.