Part 1
XII. Wherefore observe that these are the very things which the Lord wished to teach to the Sadducees, who did not believe in the resurrection of the flesh. For this was the opinion of the Sadducees. Whence it was that, having contrived the parable about the woman and the seven brethren, that they might cast doubt upon the resurrection of the flesh, “There came to Him,” it is said, “the Sadducees also, who say that there is no resurrection.” Christ, then, if there had been no resurrection of the flesh, but the soul only were saved, would have agreed, with their opinion as a right and excellent one. But as it was, He answered and said, “In the resurrection they neither marry, nor are given in marriage, but are as the angels in heaven,” not on account of having no flesh, but of not marrying nor being married, but being henceforth incorruptible. And He speaks of our being near the angels in this respect, that as the angels in heaven, so we also in paradise, spend our time no more in marriage-feasts or other festivities. but in seeing God and cultivating life, under the direction of Christ. For He did not say “they shall be angels,” but like angels, in being, for instance, crowned, as it is written, with glory and honour; differing a little from the angels, while near to being angels. Just as if He had said. while observing the fair order of the sky, and the stillness of the night, and everything illumined by the heavenly light of the moon, “the moon shines like the sun.” We should not then say that He asserted that the moon was absolutely the sun, but like the sun. As also that which is not gold, but approaching the nature of gold, is said not to be gold, but to be like gold. But if it were gold, it would be said to be, and not to be like, gold. But since it is not gold, but approaching to the nature of it, and has the appearance of it, it is said to be like gold; so also when He says that the saints shall. in the resurrection be like the angels, we do not understand Him to assert that they will then be actually angels, but approaching to the condition of angels. So that it is most unreasonable to say, “Since Christ declared that the saints in the resurrection appear as angels, therefore their bodies do not rise,” although the very words employed give a clear proof of the real state of the case. For the term “resurrection” is not applied to that which has not fallen, but to that which has fallen and rises again; as when the prophet says, “I will also raise up again the tabernacle of David which has fallen down.” Now the much-desired tabernacle of the soul is fallen, and sunk down into “the dust of the earth.” For it is not that which is not dead, but that which is dead, that is laid down. But it is the flesh which dies; the soul is immortal. So, then, if the soul be immortal, and the body be the corpse, those who say that there is a resurrection, but not of the flesh, deny any resurrection; because it is not that which remains standing, but that which has fallen and been laid down, that is set up; according to that which is written, “Does not he who fills rise again, and he who turns aside return?”
XIII. Since flesh was made to border on incorruption and corruption, being itself neither the one nor the other, and was overcome by corruption for the sake of pleasure, though it was the work and property of incorruption; therefore it became corruptible, and was laid in the dust of the earth. When, then, it was overcome by corruption, and delivered over to death through disobedience, God did not leave it to corruption. to be triumphed over as an inheritance; but, after conquering death by the resurrection, delivered it again to incorruption, in order that corruption might not receive the property of incorruption, but. incorruption that of corruption. Therefore the apostle answers thus, “For this corruptible must put on incorruption, and this mortal must put on immortality.” Now the corruptible and mortal putting on immortality, what else is it but that which is “sown in corruption and raised in incorruption,” — for the soul is not corruptible or mortal; but this which is mortal and corrupting is of flesh—in order that, “as we have borne the image of the earthy, we shall also bear the image of the heavenly?” For the image of the earthy which we have borne is this, “Dust you are, and unto dust shall you return.” But the image of the heavenly is the resurrection from the dead, and incorruption, in order that “as Christ was raised up from the dead by the glory of the Father, so we also should walk in newness of life.” But if any one were to think that the earthy image is the flesh itself, but the heavenly image some other spiritual body besides the flesh; let him first consider that Christ, the heavenly man, when He appeared, bore the same form of limbs and the same image of flesh as ours, through which also He, who was not man, became man, that “as in Adam all die, even so in Christ shall all be made alive.” For if He bore flesh for any other reason than that of setting the flesh free, and raising it up, why did He bear flesh superfluously, as He purposed neither to save it, nor to raise it up? But the Son of God does nothing superfluously. He did not then take the form of a servant uselessly, but to raise it up and save it. For He truly was made man, and died, and not in mere appearance, but that He might truly be shown to be the first begotten from the dead, changing the earthy into the heavenly, and the mortal into the immortal. When, then, Paul says that “flesh and blood cannot inherit the kingdom of God,” he does not give a disparaging opinion of the regeneration of the flesh, but would teach that the kingdom of God, which is eternal life, is not possessed by the body, but the body by the life. For if the kingdom of God, which is life, were possessed by the body, it would happen that the life would be consumed by corruption. But now the life possesses what is dying, in order that “death may be swallowed up in victory” by life, and the corruptible may he seen to be the possession of incorruption and immortality, while it becomes unbound and free from death and sin, but the slave and servant of immortality; so that the body may be the possession of incorruption, and not incorruption that of the body.
Source: From the Discourse on the Resurrection (New Advent)