2 Thessalonians 2:4, 8

who opposes and exalts himself [so proudly and so insolently] above every so-called god or object of worship, so that he [actually enters and] takes his seat in the temple of God, publicly proclaiming that he himself is God. [Ezek 28:2; Dan 11:36, 37]

Then the lawless one [the Antichrist] will be revealed and the Lord Jesus will slay him with the breath of His mouth and bring him to an end by the appearance of His coming. [Is 11:4]