If indeed they be Greeks who raise these doubts, we shall have numberless things to say to them. What then? For there are among them those who convey souls into plants, and shrubs, and dogs. Tell me, which is more easy, to resume one's own body, or that of another? Others again say that they are consumed by fire, and that there is a resurrection of garments and of shoes, and they are not ridiculed. Others say atoms. With them, however, we have no argument at all; but to the faithful, (if we ought to call them faithful who raise questions,) we will still say what the Apostle has said, that all life springs from corruption, all plants, all seeds. Do you see not the fig tree, what a trunk it has, what stems, how many leaves, and branches, stalks, and roots, occupying so much ground and embosomed therein. This then, such and so great as it is, springs from the grain which was thrown into the ground and itself first corrupted. And if it be not rotted and dissolved, there will be none of these things. Tell me, whence does this happen? And the vine too, which is so fair both to see and to partake of, springs from that which is vile in appearance. And what, tell me, is not the water that descends from above one thing? How is it changed into so many things? For this is more wonderful than the Resurrection. For there indeed the same seed and the same plant is the subject, and there is a great affinity. But here tell me how, having one quality and one nature, it turns into so many things? In the vine it becomes wine, and not only wine, but leaves and sap. For not only is the cluster of grapes, but the rest of the vine nourished by it. Again, in the olive (it becomes) oil, and the other so numerous things. And what is wonderful, here it is moist, there dry, here sweet there sour, here astringent, elsewhere bitter. Tell me how it turns into so many things? Show me the reason! But you cannot.
And in the case of yourself, tell me, for this comes nearer, this seed, that is deposited, how is it fashioned and molded into so many things? How into eyes? How into ears? How into hands? How into heart? Are there not in the body ten thousand differences of figures, of sizes, of qualities, of positions, of powers, of proportions? Nerves and veins and flesh and bones and membranes, and arteries and joints and cartilages, and as many more things beside these, as the sons of the physicians precisely specify, which compose our nature— and these come from that one seed! Does not this then seem to you much more difficult than those things? How is the moist and soft congealed into the dry and cold, that is, bone? How into the warm and moist, which are united in the blood? How into the cold and soft, the nerve? How into the cold and moist, the artery? Tell me, whence are these things? Are you not quite at a loss about these things? Do you not see every day a resurrection and a death taking place in the periods of our life? Whither is our youth gone? Whence is our age come? How is it that he who is grown old cannot indeed make himself young, but begets another, a very young child, and what he cannot give to himself, that he bestows upon another?
This also we may see in trees and in animals. And yet that which gives to another ought first to bestow upon itself. But this is what human reasoning demands. But when God creates, let all things give way. If these things are so difficult, nay, so excessively difficult, I am reminded of those mad persons, who are curious about the incorporeal Generation of the Son. Things that take place every day, that are within the grasp of our hands, and that have been enquired into ten thousand times, no one has yet been able to discover; tell me, then, how is it they are curious about that secret and ineffable Generation? Is not the mind of such men wearied in treading that void? Has it not been whirled into ten thousand giddinesses? Is it not dumfounded? And yet not even so are they instructed. When they are able to say nothing about grapes and figs, they are curious about God! For tell me, how is that grape-stone resolved into leaves and stems? How before this were they not in it, nor seen in it? But it is not the grape-stone, you say, but all is from the earth. Then how is it that without this the earth bears nothing of itself? But let us not be void of understanding. What takes place is neither from the earth, nor from the grape-stone, but from Him who is Lord both of the earth and of its seeds. For this reason He has caused the same thing to be made both without them, and with them. In the first place, showing His own power, when he said, “Let the earth bring forth the herb of grass.” And secondly, besides showing His power, instructing us also to be laborious and industrious.
Why then have these things been said by us? Not idly, but that we may believe also in the Resurrection, and that, when we again wish to apprehend something by our reasonings, but do not find it, we may not be angry and take offense, but discreetly withdrawing and checking our reasoning, we may take refuge in the power and skillfulness of God. Knowing these things therefore, let us put a curb upon our reasonings. Let us not transgress our bounds, nor the measures that have been assigned to our knowledge. For, “If any man,” he says, “thinks that he knows anything, he knows nothing yet as he ought to know.”
I speak not concerning God, he says, but concerning everything. For what? Would you learn about the earth? What do you know? Tell me. How great is its measure? What is its size? What is its manner of position? What is its essence? What is its place? Where does it stand, and upon what? None of these things can you tell? But that it is cold, and dry, and black, this you can tell— and nothing farther. Again, concerning the sea? But there you will be reduced to the same uncertainty, not knowing where it begins, and where it ends, and upon what it is borne, what supports the bottom of it, and what sort of place there is for it, and whether after it there is a continent, or it ends in water and air. And what do you know of the things that are in it? But what? Let me pass over the elements. Would you have us select the smallest of plants? The unfruitful grass, a thing which we all know, tell me, how it is brought forth? Is not the material of it water, and earth, and dung? What is it that makes it appear so beautiful, and have such an admirable color? Whence does that beauty so fade away? This is not the work of water, or of earth. Do you see that there is everywhere need of faith? How does the earth bring forth, how does it travail? Tell me. But you can tell me none of these things.
Source: Homilies on First Thessalonians (New Advent)