What does it mean that there will be a great falling away before Christ returns (2 Thessalonians 2:3)?

(V. 3) With the Word of God in our hands the saints have no excuse for being deceived. Honorable self-judgment and honest exercise of soul to do the will of God will, with the Word of God open, preserve the soul from falsehood. Let us approach it, therefore, both in thorough distrust of ourselves and in fullest confidence in Him who has given us of His Spirit, for this passage tells us of Satan's masterpiece of deception, to be manifested publicly only after the Church is taken to glory, yet whose doctrine of falsehood has preceded him in the world. "The day of the Lord" will not be until "the apostasy" has come. This is of course a revulsion against the truth of Christianity, the rejection of Scripture as being from God, the rejection of Christ as being Himself the revelation of the glory of God. This will be seen in the very realm in which Christianity was once professed, for it is the abandonment of what was once acknowledged. It is this that opens the way to the grossest deception of Satan. In any complete way this will not be true until the Church is taken to heaven, though we may even now be deeply alarmed at the large-scale giving up of the truth of God in many so-called Christian denominations of our day. These are signs of the nearness of the apostasy and therefore indicate that the rapture of His own is most near.

(1) In 1 Tim. 4 it is only "some in later times" who apostatise from the faith, giving heed to seducing spirits and doctrines of demons, through the hypocrisy of men that speak lies, branded in their own conscience, etc. It is an ascetic departure from the faith in the pretension to superior sanctity, but real denial of God's rights as Creator and grace as Saviour. In 2 Thess. 2 it is no such partial turning away, but the extreme and general defection from the gospel which will boldly issue in the abandonment of all revealed truth and of what may be called natural religion, the testimony to the Godhead in creation and man's conscience. It is the revolt which the prophetic word declares shall characterise the end of this age, as is so largely and variedly revealed in the Law, the Psalms, and the Prophets, in the Gospels, the Epistles, and the Revelation. Deut. 31, Deut. 32, Psalms 10 - 14, Isa. 65, Isa. 66, Dan. 7:8, 11, 25, Dan. 9:27, may suffice for the Old Testament. In the New one may cite Matt. 12:31-32, 43-45, Luke 17:26-30, Luke 18:8, 2 Tim. 4:4, besides 2 Thess. 2, 2 Peter 3, Jude, and Revelation throughout. These Scriptures warrant the awful expectation that both Jews and Christians will abandon their profession of the truth for which they are respectively responsible, and God be left publicly and in general without a witness of His truth and glory here below, save in the confession of a persecuted remnant and in the execution of His solemn and ever deepening strokes of judgment.

Our Authorised translators have utterly weakened the sense by rendering ἡ ἀπ. "a" falling away. Beyond doubt it is "the apostacy," and there is no ground whatever for depriving the phrase of its intentionally definite force. Nobody can pretend that it is abstract; and a quality would not have the article in Greek more than in English, so that Archbishop Newcome was as wrong in the principle as in the particular case. In the New Testament the word occurs only in Acts 21:21, and there is anarthrous, which testifies to the emphasis here expressed. There however it means "apostacy" though not "the apostacy" as here. This is better than softening it to falling away or forsaking. A verbal form occurs in 1 Tim. 4:1, where "apostatise" should have been preserved both for the sake of consistency, and to maintain the definite expression of religious defection. For this it means, not corruption but abandonment, as politically it expresses revolt from authority. See the Septuagint for its use in both these ways.

First Thessalonians was the first written by the apostle; the second epistle was written shortly after. Thus, from the beginning of revealed Christianity, from the first communications of the Spirit of God to the churches, such is the solemn warning. Those who profess the gospel will abandon it before the end comes, for that day will not come “except there come the falling away first.” It is not merely a falling away here and a falling away there, but the falling away, the apostasy in the fullest sense.

The last stage of development is found in 2 Thessalonians 2, and there we learn that ere the Day of the Lord sets in there will come the apostasy, and the revelation of the Man of Sin. "A falling away" (ver. 3), is far too vague a rendering; "the apostasy" is what the Apostle wrote. The language is terribly precise, and its significance is solemn beyond expression. It means nothing less than the total abandonment of the very name of Christianity. Individual apostates there have ever been; we have yet to behold the absolute blotting out of all profession of the Christian faith.

The apostasy will occur as far as Christendom extends. Wherever the gospel has been preached, or at any rate the Lord professed, the apostasy will be the issue. It does not mean the end of the Jews or of the heathen. The apostle is here speaking of that broad scene wherein the Lord's name has been professed. Christendom has not yet abandoned openly and avowedly the New Testament as a falsehood, and the Saviour as an impostor. It is surely coming for Protestants as well as Papists, and all the rest. The day of the Lord cannot come till all is fully out. “Because [it will not be] except the falling away shall have first come, and the man of sin been revealed.”

The first thing is the apostasy, not of the Jews (this we have seen in Daniel), but of Christendom, and it will necessarily happen before the execution of the judgment - before the day of Christ; as must also the appearance of the "man of sin," who is clearly not the apostasy itself, but, I judge, follows and winds it up. The apostle marks the two events before the judgment: viz., the coming in of the apostasy, and the revelation of the man of sin - the son of perdition (an expression which signifies that he possesses this name, by his nature, his character, and his acts) "who opposes and exalts himself against all that is called God, or is worshipped." Read to verse 10.

The coming of the Lord then is bound up closely with the gathering of the saints; the day of the Lord with the execution of judgment on His enemies here below. Hence we find here, "let no man deceive you by any means." It is evident there might be a great deal of mistake on this subject; "for that day shall not come except there come the falling away (or apostasy) first." "That day shall not come" is an insertion of our translators, marked therefore by italics, though, I believe, substantially correct. The "day" will come after the apostasy, the public abandonment of Christianity throughout Christendom.

He tells them in verse 3 not to let any deceive them, for the day of the Lord will not come until the apostasy first comes, and the man of sin is revealed. The apostasy, or the falling away, is the giving up of the profession of Christianity, and if not of the form that is outward, there will certainly be the abandonment of the foundation truths of the Gospel. Nor will this be confined to what is Christian, for even among the Jews there will no doubt be the giving up of the religious teaching professed by the orthodox among them, and that will be tenaciously held by a small remnant till the end.

The Apostle Paul in 2 Thess. 2:3, warns the Saints of a definite defection which he terms the "Apostasy" or "Falling Away," He shows that before the Man of Sin is revealed, there will come a very decided falling away from the truth as it is held in faith and love by the people of God.