The falling away is due to the persecution!.
Not according to Paul who wrote of the falling away. He ties it to the deception the AC brings and the lie God makes them believe.
2Th 2:1 Now we beseech you, brethren, by the coming of our Lord Jesus Christ, and by our gathering together unto him,
2Th 2:2 That ye be not soon shaken in mind, or be troubled, neither by spirit, nor by word, nor by letter as from us, as that the day of Christ is at hand.
2Th 2:3 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;
2Th 2:4 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, shewing himself that he is God.
That is the Antichrist!
2Th 2:5 Remember ye not, that, when I was yet with you, I told you these things?
2Th 2:6 And now ye know what withholdeth that he might be revealed in his time.
2Th 2:7 For the mystery of iniquity doth already work: only he who now letteth will let, until he be taken out of the way.
2Th 2:8 And then shall
that Wicked be revealed, whom the Lord shall consume with the spirit of his mouth, and shall destroy with the brightness of his coming:
The context is regarding the timing of the return of Christ. That cannot happen until two important things occur.
1. The falling away/Apostasy
2. and the revealing of the Antichrist
Obviously it is his appearance which causes the falling away because they fall away from Christ to him, the AC or false christ.
So it hasn't happened and isn't happening now. The AC must appear which will be a global event, then those who had followed Christ will follow the AC. Why? IMO he will claim to be Christ so they won't realize they have fallen away from Christ. This happened during the tribulation and as Christ states in Matthew, the second coming is not until the trib has ended.
Why did Paul even write this? Because people were concerned Jesus could just return at any moment without any warning (like a thief in the night) and Paul wanted to clarify that certain events had to happen first. Paul accidentally started the notion of the second coming happening at any time which is the basis for the pre-trib doctrine.
Contextually Paul was not speaking of a long period of falling away. It was a special event where people would stop being Christians and have a new God to worship and it is tied directly to the tribulation and the AC claiming to be God! Clearly it is when people are deceived and begin worshiping the AC because they think he is God.
2Th 2:3 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;
2Th 2:4 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, shewing himself that he is God.
This has not yet happened but it is coming. Remember that the falling away is directly related to someone claiming to be God. They "fall away" to that false god.
2Th 2:8 And then shall that Wicked be revealed, whom the Lord shall consume with the spirit of his mouth, and shall destroy with the brightness of his coming:
2Th 2:9 Even him, whose coming is after the working of Satan with all power and signs and lying wonders,
2Th 2:10 And with all deceivableness of unrighteousness in them that perish; because they received not the love of the truth, that they might be saved.
2Th 2:11
And for this cause God shall send them strong delusion, that they should believe a lie:
2Th 2:12 That they all might be damned who believed not the truth, but had pleasure in unrighteousness.
Nothing here about falling away due to persecution. It's a false god and lies and deception and delusion which causes the falling away.