Firstly, here’s the verse:

“let not any one deceive you in any manner, because — if the falling away may not come first, and the man of sin be revealed — the son of the destruction, who is opposing and is raising himself up above all called God or worshipped, so that he in the sanctuary of God as God hath sat down, shewing himself off that he is God — [the day doth not come].” (2 Thessalonians 2:3 – 4)

Now the “literal” explanation (God is not a trickster that is why He speaks “literally”):

The identification key for the Antichrist and his doctrine = “destruction” or “perdition” in 2 Thessalonians 2:3 – 4 (e.g. Kill in the name of god, kill in the name of justice, sadistic torture in an eternal hell, teaching to sin more, lacking holy & rehabilitative doctrine of Truth, bent on teaching and spreading hate & violence, void of True (good) knowledge & wisdom in accordance of sound doctrine, given up to the love of money, doing business in the name of God profaning His Church with Mammon led false gospels etc…).

How it “may” happen?

A couple of “visions of hell” with the “antichrist” (the beast) adding the word “eternal” to it after performing some deceiving “signs & wonders” will make “them” (whose names are not written in the Book of Life) to crawl to the lawless one. Just maybe, he will declare himself as the “gods” (or aliens) which created mankind and all the scientists will be “worshipping” him on their knees (finally).

Ever wondered how the antichrist will make himself God and deceive the masses? (2 Thessalonians 2:3 – 4)

One “possibility” = Theosis.
Yes, it’s entirely possible that he may teach some form of Theosis which underlines a central “error” that “we are also gods” or that “we will become one with god”.

All Theosis is false and against the Bible.
Please don’t be deceived!

How do we know which (interpretation of the Bible or Teaching) is right?

“See, I have told you ahead of time.” – Lord Jesus Christ in (Matthew 24:25)

As apostle Paul echoed in the past:

“wherefore I take you to witness this day, that I [am] clear from the blood of all, for I did not keep back from declaring to you all the counsel of God.” (Acts 20:26 – 27)