2 Thessalonians 2:3-4

3Let no one in any way deceive or entrap you, for that day will not come unless the apostasy comes first [that is, the great rebellion, the abandonment of the faith by professed Christians], and the man of lawlessness is revealed, the son of destruction [the Antichrist, the one who is destined to be destroyed],

4who 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.