2.64. Jesus was only a single person but He was nonetheless more things than one, according to the different standpoints from which He was assessed. Not everyone who looked at Him saw Him the same way. It is clear that He was more things than one from the saying: “I am the Way, the Truth, and the Life” (Jn. 14:6); and again “I am the bread” (Jn. 6:35), and again “I am the door” (Jn. 10:7), and innumerable others. When men looked at Him He did not appear the same way to all who saw Him, but rather according to their individual capacity to receive him. This will be clear to those who notice that He did not admit all His disciples when He was about to be transfigured on the high mountain, only Peter, James, and John, because they were capable of seeing His glory on that occasion, and of looking at the glorified aspect of Moses and Elijah, and listening to their conversation and the voice from the heavenly cloud. I also think that He did not appear as the same person to the sick and those who needed strength, as He did to those who were strong enough to ascend the mountain with Him. The following saying shows that He did not always have the same appearance, when Judas who was about to betray Him said to the crowds accompanying Him who did not know Jesus: “Whoever I kiss, that is the one” (Mt. 26:48). And I think the Savior Himself indicates the same thing by the words: “I sat every day in the Temple, teaching, and you did not lay hold of me” (Mt. 26:55). We hold, then, these lofty views on Jesus, not only in regard to the deity within, which lay hidden from the view of the crowd, but even with respect to the transfiguration of His body which took place whenever He wished, for whoever He wished. We conclude that before Jesus had put off the principalities and powers (cf. Col. 2:13-20, viz. before the complete fulfillment of the economy of salvation at the Cross and Resurrection), and so long as He was still not dead to all sin, then all men were capable of seeing Him; but when He had put off the principalities and powers and no longer had anything which was capable of being seen by the multitude, then all those who had formerly seen Him were now incapable of seeing Him. And therefore, to spare them, He did not show Himself to all men after His resurrection from the dead.’
2.65. Why do I say “to all” because even with His own apostles and disciples He was not present all the time, and He did not show Himself constantly even to them, for they were not able to receive His divinity without interruption. His deity was more resplendent once He had finished the Economy. Peter, called Kephas, the firstfruits as it were of the apostles, was able to see this, and along with him the Twelve (for Matthias was substituted in place of Judas); and after them He appeared to the five hundred brethren at once, and then to James, and subsequently to all the others besides the twelve apostles, perhaps also to the Seventy, and lastly to Paul. NO one could reasonably blame Jesus for not having admitted all His apostles to the high mountain at His transfiguration when He was about to manifest the splendor that appeared in His garments, and the glory of Moses and Elijah talking with Him. He only admitted the three we have spoken of. In the same way no one can reasonably object to the apostles who tell us that the vision of Jesus after His resurrection was not given to all men, but only to those He knew to have received eyes capable of seeing His resurrection.
6.68. So if Celsus were to ask us how we think we know God, and how we shall be saved by Him, we would answer that the Word of God who enters into those who seek Him, or who accept Him when He appears, is the one who can make known and reveal the Father. Before the appearance of the Word no man saw the Father. For who else is able to save the soul of man and conduct it to the God of all things except God the Word, who “was in the beginning with God” (Jn. 1:1)? He became flesh for the sake of those who had clung to the flesh, and had become as flesh, so that those who could not see Him as the Word, with God, God Himself, might be enabled to receive Him. And so He spoke in bodily form and announced Himself as flesh in order to call to Himself those who are flesh. He did this in the first place to effect their transformation according to the Word that was made flesh, and secondly, to lead them on high so that they can see Him as He was before He become flesh. And they received this benefit and rose up from their great introduction to Him in the flesh and said: “Even if we have known Christ after the flesh, henceforth we know Him so no more” (2 Cor. 5:16). And so He became flesh, and having become flesh, He tabernacled among us (Jn. 1:14a), not dwelling outside us. And after tabernacling and dwelling within us He did not continue in that form in which He first presented Himself, but made us ascent the lofty mountain of His word, and there showed us His own glorious form and the splendor of His garments. He showed us, as well as His own form, the form of the spiritual law, which is Moses, seen in glory alongside Jesus. He also showed us all prophecy, which even after His incarnation did not perish but was received up into heaven, which is symbolized by Elijah. The one who saw these things could say: “We behold His glory, the glory of the only-begotten of the Father, full of grace and truth” (Jn. 1:14b. Origen also applies Jn. 12:42 to the Transfiguration.).
~Contra Celsum, 2.64-65 and 6.68