1 John 3:2

"Beloved," says he, "now are we the sons of God," not by natural affection, but because we have God as our Father. For it is the greater love that, seeing we have no relationship to God, He nevertheless loves us and calls us His sons. "And it has not yet appeared what we shall be;" that is, to what kind of glory we shall attain. "For if He shall be manifested,"— that is, if we are made perfect, — "we shall be like Him," as reposing and justified, pure in virtue, "so that we may see Him" (His countenance) "as He is," by comprehension.

In like manner John says: "And it doth not yet appear what we shall be: we know, however, that when He shall be manifest, we shall be like Him." We are far indeed from being already what we know not of; we should, of course, be sure to know it if we were already (like Him).

By writing these things John is exhorting his readers to recognize what it means to be born again of God. He tells them that they are now worthy to be loved as children of God, even in this world, and that the adoption of sons is a reality here and now. For since we now know in part and have the first fruits of the Spirit, we already have something of the adoption of sons and can see what the fullness of it will be like when it arrives.

For us then, what are we? Already we are begotten of Him; but because we are such in hope, he saith, "Beloved, now are we sons of God." Now already? Then what is it we look for, if already we are sons of God? "And not yet," saith he, "is it manifested what we shall be." But what else shall we be than sons of God? Hear what follows: "We know that, when He shall appear, we shall be like Him, because we shall see Him as He is." Understand, my beloved. It is a great matter: "We know that, when He shall appear, we shall be like Him; for we shall see Him as He is." In the first place mark, what is called "Is." Ye know what it is that is so called. That which is called "Is," and not only is called but is so, is unchangeable: It ever remaineth, It cannot be changed, It is in no part corruptible: It hath neither proficiency, for It is perfect; nor hath deficiency, for It is eternal. And what is this? "In the beginning was the Word, and the Word was with God, and the Word was God." And what is this? "Who being in the form of God, thought it not robbery to be equal with God." To see Christ in this sort, Christ in the form of God, Word of God, Only-Begotten of the Father, equal with the Father, is to the bad impossible. But in regard that the Word was made flesh, the bad also shall have power to see Him: because in the day of judgment the bad also will see Him; for He shall so come to judge, as He came to be judged. In the selfsame form, a man, but yet God: for "cursed is every one that putteth his trust in man." A man, He came to be judged, a man, He will come to judge. And if He shall not be seen, what is this that is written, "They shall look on Him whom they pierced?" For of the ungodly it is said, that they shall see and be confounded. How shall the ungodly not see, when He shall set some on the right hand, others on the left? To those on the right hand He will say, "Come, ye blessed of my Father, receive the kingdom:" to those on the left He will say, "Go into everlasting fire." They will see but the form of a servant, the form of God they will not see. Why? because they were ungodly; and the Lord Himself saith, "Blessed are the pure in heart, for they shall see God." Therefore, we are to see a certain vision, my brethren, "which neither eye hath seen, nor ear hath heard, nor hath entered into the heart of man:" a certain vision, a vision surpassing all earthly beautifulness, of gold, of silver, of groves and fields; the beautifulness of sea and air, the beautifulness of sun and moon, the beautifulness of the stars, the beautifulness of angels: surpassing all things: because from it are all things beautiful.

What then shall "we" be, when we shall see this? What is promised to us? "We shall be like Him, for we shall see Him as He is." The tongue hath done what it could, hath sounded the words: let the rest be thought by the heart. For what hath even John himself said in comparison of That which Is, or what can be said by us men, who are so far from being equal to his merits? Return we therefore to that unction of Him, return we to that unction which inwardly teacheth that which we cannot speak: and because ye cannot at present see, let your part and duty be in desire. The whole life of a good Christian is an holy desire. Now what thou longest for, thou dost not yet see: howbeit by longing, thou art made capable, so that when that is come which thou mayest see, thou shalt be filled. For just as, if thou wouldest fill a bag, and knowest how great the thing is that shall be given, thou stretchest the opening of the sack or the skin, or whatever else it be; thou knowest how much thou wouldest put in, and seest that the bag is narrow; by stretching thou makest it capable of holding more: so God, by deferring our hope, stretches our desire; by the desiring, stretches the mind; by stretching, makes it more capacious. Let us desire therefore, my brethren, for we shall be filled. See Paul widening, as it were, his bosom, that it may be able to receive that which is to come. He saith, namely, "Not that I have already received, or am already perfect: brethren, I deem not myself to have apprehended." Then what art thou doing in this life, if thou have not yet apprehended? "But this one thing [I do]; forgetting the things that are behind, reaching forth to the things that are before, upon the strain I follow on unto the prize of the high calling." He says he reaches forth, or stretches himself, and says that he follows "upon the strain." He felt himself too little to take in that "which eye hath not seen, nor ear heard, neither hath entered into the heart of man." This is our life, that by longing we should be exercised. But holy longing exercises us just so much as we prune off our longings from the love of the world. We have already said, "Empty out that which is to be filled." With good thou art to be filled: pour out the bad. Suppose that God would fill thee with honey: if thou art full of vinegar, where wilt thou put the honey? That which the vessel bore in it must be poured out: the vessel itself must be cleansed; must be cleansed, albeit with labor, albeit with hard rubbing, that it may become fit for that thing, whatever it be. Let us say honey, say gold, say wine; whatever we say it is, being that which cannot be said, whatever we would fain say, It is called-God. And when we say "God," what have we said? Is that one syllable the whole of that we look for? So then, whatever, we have had power to say is beneath Him: let us stretch ourselves unto Him, that when He shall come, He may fill us. For "we shall be like Him; because we shall see Him as He is."

Despite the measure of likeness which we find in God’s Word, we also recognize a great unlikeness to God and his Word in this enigma. We must admit that even when we are like him and shall see him as he is (words which clearly imply an awareness of our present unlikeness), we shall still have no natural equality with him. For the created nature must always be less than the Creator.

Therefore we live as children of God even in this present life, sanctifying ourselves by virtue and striving toward the likeness of something even better. Encouraged by this, we shall be fashioned according to the brightness of the resurrection, when we shall see him, insofar as that is possible, as he is.

Is there any connection between what John says here and what Paul says when he writes: “God has revealed it to us by his Spirit. For the Spirit searches everything, even the deep things of God”? What then shall we be like? The answer is that here John says that he does not know what form the coming deification through the virtues of faith will take for those who are children of God here on earth now. The independently existing nature of the good things to come has not yet been revealed in detail. Here on earth we walk by faith, not by sight. Paul on the other hand says that through revelation we have received the divine promise concerning the good things which are to come but does not claim to know what these are in any detail. Thus he says quite clearly that he examines himself and pursues the higher calling as far as he understands what it is. Any contradiction between the two apostles is merely apparent, not real, because they are both inspired by the same Spirit.

Dearest, now we are children of God, and it has not yet appeared what we shall be. And Paul says: For you are dead, and your life is hidden with Christ in God (Colossians III). A faithful one is dead through the extinguishing of the old life which was in sins, and has a new life in Christ through faith, the height of which is not yet visibly apparent to us.

Because we will see Him as He is. To be God is to remain eternally and immutably. Whence to Moses He says: "I am who am" (Exod. III); and: "You shall say to the children of Israel: He Who Is has sent me to you" (Ibid.). Therefore, we will see Him as He is, when we will contemplate Him in the very substance of His divinity, which in this life is granted to no one among the elect. Even the legislator, who was accustomed to contemplating the Lord in an angelic guise, beseeched, saying: "Lord, show me Yourself that I may see You" (Exod. XXXIII), and heard from the same Lord: "No one shall see my face and live" (Ibid.). However, to him, for the merit of great sanctity, He said: "I will show you all good" (Ibid.). Hence Paul also said: "Now we see through a glass in a riddle, but then face to face" (I Cor. XIII). Therefore, what was answered to Moses is true, that no one can see the face of God and live (Exod. XXXIII), which is to say, no one living in this life can see Him as He is. Many have seen, but what the will of God chose, not what nature formed. And that which John said can rightly be understood as: "Beloved, we are children of God, and it has not yet appeared what we shall be. But we know that when He appears, we shall be like Him, because we will see Him as He is." Not as men saw Him when He willed, in the guise in which He willed, not in the nature which remained hidden in himself even when He was seen; but as He is, which was requested of Him by Moses when he said: "Show me Yourself" (Exod. XXXIII), by Him who spoke with him face to face. Not that anyone has comprehended the fullness of God, not only with the eyes of the body but even with the mind itself. For it is one thing to see, another to comprehend fully by seeing. Therefore, what is seen is what is perceived as present in whatever way, but the whole is comprehended by seeing, as nothing of it is hidden from the one seeing, or of which the limits can be circumscribed, as nothing is hidden from you of your present will. However, you can circumscribe the limits of your ring. For example, I have given two examples, one of which pertains to the mind's sight, the other to the bodily eyes. For sight must be referred to both, that is, both to the eyes and the mind.

We know that when He appears, we shall be like Him. And Paul explains this too in other words: When Christ (he says) your life appears, then you also will appear with Him in glory (Colossians III). He says we shall be like Him, for when we enjoy the immutable and eternal contemplation of divinity, we ourselves shall also be immortal. And indeed we shall be like Him, because we will be blessed; and yet, similar to the Creator because we are creatures; for who among the children of God will be like God? Even though this might also be thought to be said about the immortality of the body. And in this too we shall be like God, but only to the Son, who alone in the Trinity took on a body, in which He died, rose again, and raised it to the heights.

See what kind of love the Father has given us, that we should be called children of God. For this reason the world does not know us, because it did not know Him. Beloved, we are now children of God, and it has not yet appeared what we shall be. But we know that when He appears, we shall be like Him; for we shall see Him as He is. And everyone who has this hope in Him purifies himself just as He is pure.
After John spoke about the assembly of antichrists and their perverse doctrine, by which they have made themselves revealed as if by a certain mark [χαρακτηρί]: and he sufficiently strengthened them, so that they would persist immovably in those things in which they had been instructed, he then adds the reward also set aside because of these things, making them stronger through the clarity of the rewards, and says: "abide in Him." (1 Jn. 2:27) Why? “So that when He appears we may have confidence.” (1 Jn. 2:28) For what is clearer or more desirable than the confidence with which we will present our labors completed in life to Christ, doing this with confidence and not experiencing shame at his coming? And since it was likely that some would ask by what works they could become pleasing to Him, John teaches this also and says: If you know that He is righteous, you know that everyone who practices righteousness is born of Him: (1 Jn. 2:29) for the righteous produces righteous ones. Furthermore, no one is unaware of how this relates to our glory and confidence: just as no one is ignorant of the greatness and quality of the love and kindness he has shown towards you.
For see what he has given us, that we should be called his children. And if this is hidden from those who are in the world, that we are the children of God, do not marvel at this: for this reason the world does not know us, because it did not know Him who adopted us as children. That the world is called a chaotic multitude, we have demonstrated in many places. Then, after John confirmed the adoption, he clearly says after this the glory and confidence or freedom that is reserved for those who have been adopted, and he says:
"Beloved, now we are children of God." But if he were to say: Indeed, Beloved, from the preceding you know that we are adopted as children of God: and if this has not yet been revealed, do not be troubled: for what is now uncertain will be revealed when He is revealed. Indeed, we will display the glory of adoption appearing as His likeness; for children are altogether like their father.
But having confidence toward Him as children, we shall see Him as He is: not certainly according to His nature; for this is impossible for created nature: but what? the righteous of the righteous, the pure of the pure. For like follows the like. For this reason, I said a little earlier that we shall be like Him: not according to nature; for otherwise He would have said not "like," but "the same," but now because this will not happen, He said "like," according to the quality of glory, indeed. It should be noted, however, that he did not say previously, "Everyone who has done or will do righteousness," but "He who does." For virtues always operate: and while they are being done, they have being; but those that cease or are to come, do not even have being.