The text says:
Originally Posted by highflyertoo
2 Thessalonians 2:3 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, 4 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. The physical temple of God was still standing in Jerusalem when Paul said that the "man of sin" would "take his seat in the temple of God." The Thessalonians would have known that he was talking about a literal person in the literal Temple that then was standing.
The identity of the "man of sin" as an apostate high priest is the best fit to the Biblical data that I have seen. It all fits well with Christ's condemnation of the Jewish leaders as a "generation of vipers" just before he predicted the destruction of the Temple in Matthew 24.