Let no one in any way deceive you, for it will not come unless the apostasy comes first, and the man of lawlessness is revealed, the son of destruction, who opposes and exalts himself above every so-called god or object of worship, so that he takes his seat in the Temple of God, displaying himself as being God. - 2 Thessalonians 2:3-4
Excuse little ole me, but this verse is referring to the apostate church that built itself up after the last Apostle died, in the first century. It made itself into "the temple of God," misleading the people into believing it was actually of God. This apostate religion has exalted itself above every so-called god, and has fooled the world into thinking that it really does represent God.
This "son of destruction" is the same thing as the apostate group that Jesus, John, Peter and Paul warned would infiltrate the Christian congregation and practically choke out the truth for a LONG time. (Matthew 13:24-30, 37-43; I John 2:18,22, 4:3; 2 Peter 2:1-3, 12-16; Acts 20:29,30)
It is part of Babylon the Great, the world empire of false religion. (Rev.17:1-6, 15-18)
"I know that after my going away [Paul's death] oppressive wolves will enter in among you and will not treat the flock with tenderness, and from among you yourselves men will rise and speak twisted things to draw away the disciples after themselves." (Acts 20:29,30)
That has been the state of affairs since the first century, after the last Apostle died. Don't be deceived into looking for a literal single man of lawlessness or another temple.