2 Thessalonians 2:2-3 (New International Version)

²not to become easily unsettled or alarmed by some prophecy, report or letter supposed to have come from us, saying that the day of the Lord has already come. ³Don't let anyone deceive you in any way, for (that day will not come) until the rebellion occurs and the man of lawlessness^[a] is revealed, the man doomed to destruction.