18 But I will explain to you, my beloved, concerning that word which the Apostle said, by which can be weighed the doctrines that are instruments of the Evil One and doctrines of deceit. For the Apostle said:— There is an animal body and there is a spiritual body, seeing that it is thus written:— The first Adam became a living soul and the second Adam a quickening spirit. So they say that there will be two Adams. But he said:— As we have put on the image of that Adam who was from the earth, so we shall put on the image of that Adam who is from heaven. For Adam who was from the earth was he that sinned, and the Adam who is from heaven is our Saviour, our Lord Jesus Christ.
They then that receive the Spirit of Christ, come into the likeness of the heavenly Adam, Who is our Saviour, our Lord Jesus Christ. For the animal shall be swallowed up in the spiritual, as I wrote unto you above. And the man that grieves the spirit of Christ, will be animal in his resurrection; because the heavenly spirit is not with him, that the animal might be swallowed up in it. But when he shall arise he shall continue in his natural state, naked of the Spirit. Because he stripped off from him the Spirit of Christ, he shall be given over to utter nakedness.
And whosoever honours the Spirit, and it is guarded in him in purity, in that day the Holy Spirit shall protect him, and he shall become altogether spiritual, and shall not be found naked; as the Apostle said:— And when we shall have clothed ourselves, may we not be found naked. And again he said:— We shall all sleep, but in the resurrection we shall not all be changed. And again he said:— This which dies shall put on that which dies not, and this which is corruptible that which is incorruptible, and when this which dies shall have put on that which dies not, and this corruptible that which is incorruptible, then shall be accomplished that word which is written that death is swallowed up by victory. Again he said:— Suddenly as the twinkling of an eye, the dead shall rise incorruptible and we shall be changed. And they who shall be changed shall put on the form of that heavenly Adam and shall become spiritual.
And those who shall not be changed, shall continue animal in the created nature of Adam, namely, of dust; and shall continue in their nature in the earth below. And then the heavenly shall be caught up to heaven and the Spirit that they have put on shall cause them to fly, and they shall inherit the kingdom that was prepared for them from the beginning. And they that are animal shall remain on the earth by the weight of their bodies, and shall turn back to Sheol, and there shall be weeping and gnashing of teeth.
Source: Demonstrations (New Advent)