Let no man... by any means. — “Whatever device they may adopt — spirit, letter, or what not — they are deceivers or deceived; do not be duped by them.” The form of warning is a mark of St. Paul’s style. (Comp. 1 Corinthians 3:18; Ephesians 5:6)
For... except. — The words between are rightly supplied in our version. Probably, St. Paul’s first intention was to turn 2 Thessalonians 2:5 differently, as, for instance:” For, except that Man of Sin, &c, ye remember that I told you the day would not come.” The length of the sentence made him break off (as he often does) without regard for grammatical completeness.
A falling away. — A great change in the purpose of the sentence will be felt directly “the” is substituted for “a.” Only one insignificant MS. omits the definite article; the same article in our version is vigorously rendered “that” before “man of sin.” In both cases the purpose is by no means to utter a new, strange prophecy, or to add to the knowledge of the readers, but to remind them of careful teaching given during the first few weeks after their conversion. “That falling away” must undoubtedly imply that the persons so apostatising had formerly held (or, perhaps, still professed to hold) the Christian faith: men cannot fall from ground which they never occupied. This vast and dreadful Apostasy (see Luke 18:8), so clearly and prominently taught of to the ancient Church, and so mysterious to us, is further defined by the following words, as the Apocalypse or Manifestation of the Man of Sin. Of this revelation of Antichrist the same word (apocalypsis) is used which is often used of Christ, as, e.g., 2 Thessalonians 1:7; Luke 17:30; and thrice in St. Peter; so that we may expect to recognise him when he comes as clearly as we shall recognise Christ. The conception of the Antichrist is not merely that of an opponent of the Christ, but of a rival Christ: there is a hideous parallelism between the two.
That man of sin. — It is not absolutely certain from the Greek, but the context makes it tolerably clear that the “Man of Sin” is the head and centre of the Apostasy itself, and does not form a separate movement from it. The “Man of Sin,” then, will have at one time formed (or will still profess to form) part of the Christian Church, and the Apostasy will culminate in him. Thus, for instance, the requirements of the passage would not be fulfilled by (with Hammond) interpreting the Apostasy to mean the early Gnostic movement, followed up by the independent appearance of Nero as the Man of Sin. The phrase, “the Man of Sin,” might, perhaps, be only a poetical personification of a movement, or of a class of men, or of a succession of men (as, e.g., Psalms 89:22; Revelation 2:20; Revelation 17:3); but the analogy of the parallel passages in Daniel 8:11 leads rather to the supposition that St. Paul looked for the coming of some actual individual man who should be the impersonation of the movement of Apostasy. The genitive (see Note on 1 Thessalonians 1:3) is like a forcible epithet:” A man so wicked that, bad as other men are, wickedness should be his mark by which he is distinguished from all others; a man who belongs to sin, in whom the ideal of sin has become realised and incarnate.” What kind of sin will be most prominent in him is not expressed in the word itself; but the context points clearly to that which is, in fact, the crowning sin — spiritual pride and rebellious arrogancy (Ephesians 6:12).
The son of perdition. — The phrase which is used, in John 17:12, of the false Apostle; it suits well with the description of the Man of Sin, who, like Judas, will have “fallen away” from high Christian privileges: according to one popular interpretation, like Judas, from the privileges of the Apostolate itself. The expression signifies one who belongs by natural ties to perdition — who from his very birth chooses evil, and in such a sense may be said to be born to be lost (Matthew 26:24; 2 Peter 2:12). Both his malignity and his doom are thus implied in it.