‘... that you not be quickly shaken from your composure or be disturbed either by a spirit or a message or a letter as if from us, to the effect that the day of the Lord has come.

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 2:2-4
NASB