Matthew 17:12

That He says of John, Elias is already come, is not to be understood of the soul of Elias, that we fall not into the doctrine of metempsychosis, which is foreign to the truth of Church doctrine, but, as the Angel had foretold, he came in the spirit and power of Elias.

But when the statement of our Redeemer from another reading is brought to mind, a very complex question arises for us from the words of this reading. For in another place, when asked by his disciples about the coming of Elijah, the Lord replied: "Elijah has already come, and they did not recognize him, but did to him whatever they wished. And if you wish to know, John himself is Elijah." But when John was asked, he says: "I am not Elijah." What is this, dearest brothers, that what Truth affirms, the prophet of Truth denies? For "He is" and "I am not" are very different from each other. How then is he a prophet of Truth if he does not agree with the words of that same Truth? But if the truth itself is carefully examined, what sounded contradictory between them is found not to be contradictory. For the angel says to Zechariah concerning John: "He will go before him in the spirit and power of Elijah." He is said to be coming in the spirit and power of Elijah because just as Elijah will precede the second coming of the Lord, so John preceded the first. Just as the former will be the precursor of the Judge, so the latter was made the precursor of the Redeemer. John therefore was Elijah in spirit; he was not Elijah in person.

Then is added concerning the other Elijah: but I say to you that Elijah has already come. Who is he? John the Baptist, not that he is the same in person, as is found in John 1:21, when it was asked of him, are you …

But I say unto you, That Elijah is come already, and they knew him not, but have done unto him whatsoever they desired. Likewise shall also the Son of Man suffer at their hands. But when Christ says, "Elijah is come already," He is speaking …

Note, When we return to the world again after an ordinance, it must be our care to take Christ with us, and then it may be our comfort that he is with us. As they came down, they talked of Christ. Note, When we are returning from holy ordinance, it is good to entertain ourselves and one another with discourse suitable to the work we have been about.

Note, God's promises are often fulfilled, and men perceive it not, but enquire, Where is the promise? when it is already performed. Elias is come, and they knew him not; they knew him not to be the Elias promised, the forerunner of the Messiah.

But I say unto you,....

Knew him not - Or, ουκ επιγνωσαν αυτον, They have not acknowledged him. That is, the Jewish rulers have not acknowledged him, did not receive him as the forerunner of the Messiah. But it appears that all the rest acknowledged him as such; and some, from the power and demonstration of his preaching, were inclined to think he was more, even the Messiah himself: see Luk 3:15.

These verses contain one of the most remarkable events in our Lord’s earthly ministry, the event commonly called the transfiguration. The order in which it is recorded is beautiful and instructive. The latter part of the last chapter showed us the cross; here we are graciously allowed to see something of the coming reward. The hearts which have just been saddened by a plain statement of Christ’s sufferings are at once gladdened by a vision of Christ’s glory. Let us mark this. We often lose much by not tracing the connection between chapter and chapter in the Word of God.

These verses contain one of the most remarkable events in our Lord’s earthly ministry, the event commonly called the transfiguration. The order in which it is recorded is beautiful and instructive. The latter part of the last chapter showed us the cross; here we are graciously allowed to see something of the coming reward. The hearts which have just been saddened by a plain statement of Christ’s sufferings are at once gladdened by a vision of Christ’s glory. Let us mark this. We often lose much by not tracing the connection between chapter and chapter in the Word of God. There are some mysterious things, no doubt, in the vision here described. It must needs be so. We are yet in the body. Our senses are conversant with gross and material things; our ideas and perceptions about glorified bodies and dead saints must necessarily be vague and imperfect. Let us content ourselves with endeavoring to mark out the practical lessons which the transfiguration is meant to teach us. In the first place we have in these verses a striking pattern of the glory in which Christ and his people will appear when he comes the second time. There can be little question that this was one main object of this wonderful vision. It was meant to encourage the disciples by giving them a glimpse of good things yet to come. That face “shining as the sun” and that raiment “white as the light” were intended to give the disciples some idea of the majesty in which Jesus will appear to the world when he comes the second time, and all his saints with him. The corner of the veil was lifted up to show them their Master’s true dignity. They were taught that if he did not yet appear to the world in the guise of a King, it was only because the time for putting on his royal apparel was not yet come. It is impossible to draw any other conclusion from St. Peter’s language when writing on the subject.