In 2 Thes 2:2, Paul wrote, “the day of Christ is at hand.” In 2 Thes 2:1-12 he described some things that will happen as we approach the second coming of Jesus Christ.
Men will be troubled – 2 Thes 2:1-2 – he warned the Thessalonians to not be “soon shaken in mind, or be troubled.” Indeed, Jesus warned his disciples about the same thing. He said, “see that ye be not troubled,” [Matt 24:6-8]. There will be news of wars, famines, pestilences, earthquakes, and other natural disasters. It’s easy to be troubled in spirit, by what you see and hear [like bad news]. It can also be troubling to hear it preached by word or to read it written in a letter [2:15].
Men will be deceived – 2 Thes 2:3 – deception is the first thing about which Jesus warned his disciples in Matt 24:4-5, 11. During the Tribulation the world will be deceived by the devil’s power, signs and lying wonders [2 Thes 2:9-10; Rev 13:11-14]. Additionally, the Lord will send strong delusion [2 Thes 2:11-12]. See Ezek 14:9 and 1 Ki 22:22-23, as examples. You get the combination of the Lord and the devil deceiving the world because they believe not and receive not the love of the truth. The only hope for them is to love the truth that they might be saved. In fact, many are saved in the Tribulation [Rev 7:9-14]. Preachers have said they couldn’t be saved in Tribulation if they didn’t get saved in the church age. As you can see, this is not true.
Men will fall away – 2 Thes 2:3 – the church age ends in apostasy. See 1 Tim 4:1, for example. Apostasy precedes the Lord’s coming, which explains the apostasy you’re seeing now. Some call the period we’re in now the Laodicean age [Rev 3:14-17]. In this age, people say that they’re rich, and increased with goods, and have need of nothing. The Lord says, they’re wretched, miserable, poor, blind and naked.
The man of sin will be revealed – 2 Thes 2:3 – the antichrist will be revealed before the Lord is revealed in 2 Thes 1:7. He will exalt himself above all that is called God and will shew himself that he is God [2 Thes 2:4; Is 14:12-14; Dan 11:36-37]. He comes in peaceably [Dan 8:25]. He sits on the throne in Jerusalem [Lam 4:12]. He is the Wicked, a man who is the devil incarnate [2 Thes 2:8]. He does miracles [2 Thes 2:9] and he has an image [Rev 13:14-16] that will stand in the holy place [Matt 24:15].
The antichrist will continue working – 2 Thes 2:6-7 – in the meantime, before the man of sin is revealed, the antichrist will continue working as the mystery of iniquity. Thus, the man of sin will be revealed “in his time.” He who now letteth is the antichrist [1 Jn 2:18, 22]. In 1 Jn 4:3, John wrote, “the spirit of antichrist… is… already in the world.” In Matt 24:23-27, Jesus warned of false Christs. Today you find these false Christs in religions like the Roman Catholic Church, the Jehovah’s Witnesses and the Latter Day Saints. “… until he be taken out of the way,” is not a reference to the Holy Spirit, as some men have taught. In Matt 10:20-22 and Heb 6:4-6, for example, the Holy Spirit is here during the Tribulation. “Until he be taken out of the way” is a a reference to “the mystery of iniquity.” It will no longer be a mystery when the man of sin, the son of perdition, is revealed.
The Wicked will be destroyed – 2 Thes 2:8 – this is the destruction of the man in which the devil will be incarnate. You see this man burned to ashes and thrown in hell in Ezek 28:15-19; Is 14:15-17. The devil himself will be chained in the bottomless pit [Rev 20:1-3].
Conclusion: since the day of Christ is at hand, don’t be troubled, don’t be deceived, and don’t fall away. Believe the truth, love the truth, and if you aren’t saved, get saved.