Here is what Apostle Paul actually taught as written in that 2 Thessalonians 2 Chapter, and it ain't about Church attendance or going back to a life of sin...
2 Thess 2:1-12
2 Now we beseech you, brethren, by the coming of our Lord Jesus Christ, and by our gathering together unto Him,
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.
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;
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.
Men's doctrines today separate the above two verses when they actually are meant to go together. Even in verse 3 above Paul associates that "falling away" with that "man of sin" being revealed. Then in the 4th verse Paul explains exactly what that "man of sin" is going to do in a traditional stone temple in Jerusalem at the end of this world, playing God, which means playing Jesus Christ.
Lord Jesus Himself warned the Church about this in His Olivet discourse of Matthew 24 and Mark 13. So what's going on in those deceived Churches; they got short memories or something to so soon forget Christ's Own warning about this coming pseudo-Christ? (See Matthew 24:23-26)
5 Remember ye not, that, when I was yet with you, I told you these things?
6 And now ye know what withholdeth that he might be revealed in his time.
7 For the mystery of iniquity doth already work: only he who now letteth will let, until he be taken out of the way.
Paul is not... speaking of The Holy Spirit in the above verses either. That's a false doctrine of men that the Pre-trib Rapture school started. Paul is pointing to Archangel Michael who will boot Satan and his angels down to earth at the end of this world after the Revelation 12:7 war in Heaven happens.
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:
9 Even him, whose coming is after the working of Satan with all power and signs and lying wonders,
When Satan is booted down to this earth by Archangel Michael, that is when this "man of sin" will be "revealed', showing up in Jerusalem playing Christ. And that is when that false one will work that "... all power and signs and lying wonders" to deceive the whole world, except Christ's elect. Those are the same great signs and wonders that Lord Jesus warned us about involving that coming false-Christ per His Olivet discourse.
Falling away from going to Church?@!$%^??? No way, it is about falling away from Jesus by being DECEIVED to worship the "another Jesus" in Christ's place! Oh, maybe you folks never read Paul's warning of 2 Corinthians 11 where he speaks of the "another Jesus" (KJV)?
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.
11 And for this cause God shall send them strong delusion, that they should believe a lie:
12 That they all might be damned who believed not the truth, but had pleasure in unrighteousness.
KJV
See that 11th verse above? Paul's falling away in that 2 Thess.2 Chapter isn't about falling away from going to Church and back to a life of sin. It is about falling away into DECEPTION TO THE ANOTHER JESUS, THE COMING FALSE-MESSIAH THAT COMES FIRST.
2 Cor 11:1-4
11 Would to God ye could bear with me a little in my folly: and indeed bear with me.
2 For I am jealous over you with godly jealousy: for I have espoused you to one Husband, that I may present you as a chaste virgin to Christ.
3 But I fear, lest by any means, as the serpent beguiled Eve through his subtilty, so your minds should be corrupted from the simplicity that is in Christ.
4 For if he that cometh preacheth another Jesus, whom we have not preached, or if ye receive another spirit, which ye have not received, or another gospel, which ye have not accepted, ye might well bear with him.
KJV
If you guys cannot grasp what Apostle Paul is warning us about in the above, then maybe I don't belong here, for only those who remain in Jesus Christ will heed the above warnings by Apostle Paul about falling away to the coming false-Messiah.