Let no man deceive you by any means: for that day shall not come, except there come a falling away first, and that man of sin be revealed, the son of perdition.
While there are no visible signs or prophecies to be fulfilled before our Lord’s return, the Apostle does tell us that before Christ’s second advent, there will be a wholesale, universal apostasy and departure from the faith.
Paul is not talking here about liberals, open heretics, and vile ungodliness. He talks about those things in other places. Here he is talking about a departure of men and women from the faith who claim to be in the faith, a subtle, deceiving, damning departure from the faith by professed believers throughout the world. Look at this third verse. Here the Holy Spirit tells us that heresies must come. They had already begun in apostolic times; and they only get worse as time passes (1 Cor. 11:19; 1 Tim. 4:1-3; 2 Tim. 3:1-9; 1 John 4:1-3). And the man of sin, antichrist, will be revealed.
Forget about what you see coming out of Hollywood and read in books of fiction, masquerading as books on Bible prophecy. This man of sin will not be revealed to the world. He is not some hideous looking, green-eyed monster in a red suit, with horns and a pitch fork. He is so smooth and slick that unless God himself enables you to recognize him, you cannot recognize him. However, he shall be revealed to God’s elect.
Who opposeth and exalteth himself above all that is called God, or that is worshipped; so that he as God sitteth in the temple of God, showing himself that he is God.
Here the Apostle identifies the antichrist, this man of sin. The antichrist is not one man.
I have no problem at all in stating as many of our forefathers did, in great faithfulness, that the pope is antichrist and the church of Rome is antichrist. I do not mean that is the way it used to be. I mean that “his unholiness,” the pope, is antichrist. I mean that Roman Catholicism is antichrist. That cannot be stated too often, or too emphatically. However, it is a serious mistake to limit antichrist to one man, or one religious sect. Antichrist was already at work in the Apostolic age. John said many antichrists had gone out into the world. Paul had to contend with antichrists at Galatia, Colosse, Corinth, and Jerusalem.
Notice how Paul describes this thing called “the man of sin, the son of perdition.” He is one who opposes God, exalts himself above God, and sits himself up in the temple of God and is worshipped as God, showing that he is God.
Antichrist is any system of religion, any man, any preacher, any church, any denomination that makes salvation to be dependent upon or determined by the will, works, and worth of man, rather than the will, works, and worth of Christ. It does not matter whether that system of religion is conservative or liberal, a mainline Protestant Church or a wild cult, Baptist or Methodist, Pentecostal or Presbyterian. Any church, doctrine, preacher, or religious system that makes man the center-piece is antichrist.
Those who teach that God’s will can be altered, hindered, or thwarted by man’s will are, according to Colossians 2, will worshippers, not God worshippers. They are antichrists. Those who teach that the merit and efficacy of Christ’s atonement resides in man’s will, man’s decision, and man’s faith are antichrists. Those who teach that the gracious operations of God the Holy Spirit may be successfully resisted by man are antichrists. Those who teach that grace can be forfeited or taken away as the result of something a man does are antichrists. – Don Fortner
Feileadh Mor 
Surely we must be careful and very biblical when we are talking about the biblical nature of “Antichrist”, which can mean either against Christ or instead of Christ, or perhaps even, combining the two, “one who, assuming the guise of Christ, opposes Christ” (Westcott). The word itself is found only in John’s Letters, where it is of the many antichrists who are actually forerunners of the Antichrist himself, (1 John 2: 18;22 / 2 John 7); which is of the evil power which already operates anticipatively of the Antichrist, 1 John 4: 3.
However, Rev. 13 also speaks of this real evil “personage”, both an age and a real person to come! We can see this too, from what the Apostle Paul says of the Man of Sin in 2 Thess. 2, “and that same person seems to be in view in all these passages, rather than the second beast in Rev. 13, the false prophet; for the latter supports the former in all his Antichristian assumptions.”
‘Note: The term “pseudochristos, a false Christ, is to be distinguished from the above; it is found in Matt. 24: 24 and Mark 13: 22. The false Christ does not deny the existence of Christ, he trades upon the expectation of His appearance, affiring that he is the Christ. The Antichrist denies the existence of the true God (Trench, Syn . …, xxx).
*I have used here: ‘W.E. Vines Expository Dictionary of New Testament Words’. Vine is always a very “spiritual” Christian man and teacher! We have had few like him at this level!
Excellent summary Robert. Thank you.
*affirming
Indeed this nails both Roman Catholicism (the Papacy, is surely antichrist by system), and the Coming full reality of Antichrist! Btw, surely the pope could or might be THE “false prophet” in Rev. 13…when that comes to fullness!
Note, I am surely Post-trib. The Church WILL see “The Antichrist” (2 Thess. 2: 3), but will we know him? i.e. Recognize him!
Btw, thanks jm for the great subject…it is right before our eyes! And Gentile Apostasy is the order also! Surely humanity cannot survive the 21 century? Thankfully I will be before the Lord well before that ends!