Let no one deceive you in any way. For it will not be, unless the departure comes first, and the man of sin is revealed, the son of destruction,
The word rendered “falling away” (ἀποστασία apostasia, apostasy), is of so general a character, that it may be applied to any departure from the faith as it was received in the time of the apostles. It occurs in the New Testament only here and in Acts 21:21, where it is rendered “to forsake” - “thou teachest all the Jews which are among us to forsake Moses” - apostasy from Moses - ἀποστασίαν ἀπὸ Μωῦσέως apostasian apo Mōuseōs. The word means a departing from, or a defection; see the verb used in 1 Timothy 4:1, “Some shall depart from the faith” - ἀποστήσονται apostēsontai; compare the notes on that passage; see also Hebrews 3:12; Luke 8:13; Acts 5:37. The reference here is evidently to some general falling away, or to some great religious apostasy that was to occur, and which would be under one head, leader, or dynasty, and which would involve many in the same departure from the faith, and in the same destruction. The use of the article here, “the apostasy” (Greek), Erasmus remarks, “signifies that great and before-predicted apostasy.” It is evidently emphatic, showing that there had been a reference to this before, or that they understood well that there was to be such an apostasy. Paul says 2 Thessalonians 2:5, that when he was with them, he had told them of these things. The writers in the New Testament often speak of such a defection under the name of Antichrist; see Revelation 13:14; 1Jo 2:18, 1 John 2:22; 1Jo 4:3; 2 John 1:7.