Who opposes and exalts himself above all that is called God, or that is worshiped; so that he as God sits in the temple of God, showing himself that he is God.
Read Chapter 2
Ambrosiaster
AD 400
so much so that he sits in the temple of God
Thus it appears that he will either be of the circumcision or at least circumcised himself, so that the Jews will have the confidence to believe in him.
presenting himself as if he were God
He will even sit in Christ's seat in the house of God and declare that he is not the Son of God, but God himself.
Some think that we should render the Greek more exactly were we to read, not “in the temple of God,” but “for” or “as the temple of God,” as if he himself were the temple of God, the Church.
so much so that he sits in the temple of God
he means, the Temple of the Jews which has been destroyed. For if the Antichrist comes to the Jews as Christ, and desires to be worshipped by the Jews, he will make great account of the Temple, that he may more completely beguile them; making it supposed that he is the man of the race of David, who shall build up the Temple which was erected by Solomon.
so much so that he sits in the temple of God
The temple, that is, in the Church, or in the temple that was destroyed by the Romans, which the Jews will then rebuild.
From this it shows that the Antichrist will overturn idolatry, which the Devil introduced, and he will put an end to every sect which opposes the word of truth.