The Bible indicates that there will be a great apostasy during the end times. The “great apostasy” is mentioned in 2 Thessalonians 2:3. The end times will include a wholesale rejection of God’s revelation, a further “falling away” of an already fallen world.The Greek word translated “rebellion” or “falling away” in verse 3 is apostasia, from which we get the English word apostasy. It refers to a general defection from the true God, the Bible, and the Christian faith.
Now, brethren, concerning the coming of our Lord Jesus Christ and our gathering together to Him, we ask you, 2 not to be soon shaken in mind or troubled, either by spirit or by word or by letter, as if from us, as though the day of [a]Christ had come. 3 Let no one deceive you by any means; for that Day will not come unless the falling away comes first, and the man of [b]sin is revealed, the son of perdition, 4 who opposes and exalts himself above all that is called God or that is worshiped, so that he sits [c]as God in the temple of God, showing himself that he is God.