Saint John Chrysostom- On the Antichrist.
"Let no one of you be deceived by any means, that if the apostasy does not appear first to reveal the man of sin, the son of perdition, the one who opposes and exalts himself above all that is God or that is worshipped, so that he as God sits in the temple of God, showing himself that he is God".
Here he talks about the antichrist and reveals great mysteries. What is apostasy? The antichrist himself he calls apostasy, because he will lead many to perdition and separate them from the faith, so that, he says, if possible to scandalize even the elect. He also calls him man of sin. Because he will perform uncountable sufferings but he will also induce others to do the same. He calls him also son of perdition, for he will be led to perdition.
But who is he really? Is he Satan? Of course not, but a man who will receive all his energies. "And the man will be revealed" he says, "who exalted himself above all that is called God or that is worshipped" meaning the antichrist. For he will not bring some idolatric religion but he will be anti-God and he will remove all Gods and he will command that he be worshipped as God and he will move in the temple of God, not only the one in Jerusalem, but he will be trying to prove that he is God. For he will perform great deeds and wondrous signs.
Later, wishing to show who he is, whose appearance will happen through the energies of Satan, he says "by all means, signs and monstrous lies". In other words, he will demonstrate all manner of miraculous capabilities, but nothing will be true but they will all be done to deceive. These things he foretold, that the Christians of his time, not be deceived. "And monstrous lies he says, meaning that with miracles they will be led to lies. "And by every deception of injustice to perdition".
Why would God permit- one could ask- such an event to happen? And what type of divine economy is this? What would be the gain from the appearance of that antichrist, since he will come to hurt us? Fear not, my dear, but listen to him who says that he will have authority only on those who will be lost anyway, who even if he did not come (the antichrist) they would not have believed. You ask therefore what would be the gain? He comes therefore to screen them. So that they may not say, that because Christ was saying that He is God- even if nowhere did He say so openly- but because He was declared to be so by His followers, that is why we did not believe. Because we heard that God is one by whom everything was created, that is why we did not believe in Christ. The antichrist will therefore exactly refute their excuse. For when he will come and they shall believe in him as he does not represent anything right but everything unlawful, they will then be silenced. For if you do not believe in Christ, so much more you should not have believed in the antichrist. For He said He was sent by the Father, he (the antichrist) however the opposite. That is why Christ said, "I came in the name of the Father and you did not receive Me. If someone else will come in his name, him you will receive".
But they will say, we have seen signs. However even by Christ many and great signs were made, So much more you should not have believed in him (the antichrist). Of course much have been foretold, that he will be unlawful, the son of perdition, that his presence will be trough the energies of Satan, while about Him the contrary that He is the Saviour, and the bearer of good works".
For they would not receive the love of truth, to save themselves. For this, God will send them deceit to believe in falsehood, to judge all those who did not believe in the truth but prosper in injustice". "That they be judged". He did not say "that they be cursed" for even without Him they were cursed but "to be judged" namely to be condemned in front of the dread seat of judgment for they will be unrepentant. Who would they be these people? He explained it Himself, adding "those who did not believe in the Truth". "For they" He says, "did not accept the love of Truth". For it was both love and truth. For these two He came to this world and because He is a lover of mankind and to reveal the truth......
The antichrist instead will come to fault the people and to destroy them. And what does he then intends to do? He will agitate everything and he will shake everything and because of them that he will shake and because of them that he will be ordering and because of the fear he will create. He will be fearsome to all, by his authority, by his brutality, by his illegal orders. Fear not though, his authority will be in force, He tells them, on those that are doomed to be lost. For then will come Elijah to protect the faithful. This was told by Christ: "Elijah will come and restore everything"...... Exactly as John was the forerunner of the first appearance of Christ, so would Elijah will be the forerunner of His second glorious appearance and for this he has not died but is preserved.
(Explanation of the 2nd Thess. epistle of Apostle Paul, Chap. 2 verses 3-12).