What does the Bible say about the great apostasy?

The great apostasy, as mentioned in 2 Thessalonians 2:3-4, refers to a significant falling away from the faith that is to occur before the return of Christ. The Apostle Paul warns his readers not to be deceived, stating that this event must happen before the revelation of 'the man of sin,' a figure representing apostate Christianity. This apostasy is characterized by those who claim to be Christian yet oppose the true teachings of God, exemplified in the papal system, which is viewed as anti-Christian. This theological perspective underscores the necessity for vigilance among believers to remain true to Scripture amidst widespread deception.