And why do I say “to all?” For even with His own apostles and disciples He was not perpetually present, nor did He constantly show Himself to them, because they were not able without intermission to receive His divinity. For His deity was more resplendent after He had finished the economy (of salvation): and this Peter, surnamed Cephas, the first-fruits as it were of the apostles, was enabled to behold, and along with him the twelve (Matthias having been substituted in room 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 to the seventy also, and lastly to Paul, as to one born out of due time, and who knew well how to say, “Unto me, who am less than the least of all saints, is this grace given;” and probably the expression “least of all” has the same meaning with “one born out of due time.”
For as no one could reasonably blame Jesus for not having admitted all His apostles to the high mountain, but only the three already mentioned, on the occasion of His transfiguration, when He was about to manifest the splendour which appeared in His garments, and the glory of Moses and Elias talking with Him, so none could reasonably object to the statements of the apostles, who introduce the appearance of Jesus after His resurrection as having been made not to all, but to those only whom He knew to have received eyes capable of seeing His resurrection.
I think, moreover, that the following statement regarding Him has an apologetic value in reference to our subject, viz.: “For to this end Christ died, and rose again, that He might be Lord both of the 'dead and living.'” For observe, it is conveyed in these words, that Jesus died that He might be Lord of the dead; and that He rose again to be Lord not only of the dead, but also of the living. And the apostle understands, undoubtedly, by the dead over whom Christ is to be Lord, those who are so called in the first Epistle to the Corinthians, “For the trumpet shall sound, and the dead shall be raised incorruptible;” and by the living, those who are to be changed, and who are different from the dead who are to be raised.
And respecting the living the words are these, “And we shall be changed;” an expression which follows immediately after the statement, “The dead shall be raised first.” Moreover, in the first Epistle to the Thessalonians, describing the same change in different words, he says, that they who sleep are not the same as those who are alive; his language being, “I would not have you to be ignorant, brethren, concerning them who are asleep, that you sorrow not, even as others which have no hope.
For if we believe that Jesus died, and rose again, even so them also that sleep in Jesus will God bring with Him. For this we say unto you by the word of the Lord, that we who are alive and remain unto the coming of the Lord, shall not prevent them that are asleep.” The explanation which appeared to us to be appropriate to this passage, we gave in the exegetical remarks which we have made on the first Epistle to the Thessalonians.
Source: Against Celsus (New Advent)