Paul did expect a falling away
The clearest passage is Paul’s letter to the Thessalonian church. Some believers there feared that the day of the Lord had already arrived, so Paul steadied them. He said certain things would happen first, including “a falling away” and the revealing of the man of sin (2 Thessalonians 2:1-3).
The Greek word translated “falling away” is apostasia. It carries the sense of revolt, defection, or turning away from a previously held allegiance. So Paul appears to describe a serious rebellion against God, not merely ordinary doubt or a season of spiritual struggle.
Let no man deceive you by any means: for that day shall not come, except there come a falling away first, and that man of sin be revealed, the son of perdition;
Jesus and the apostles gave similar warnings
Jesus warned His disciples that false prophets would arise and lead many astray. He also spoke of love growing cold because wickedness would increase, while calling His followers to endure faithfully (Matthew 24:11-13). These warnings make room for a widespread turning from truth, especially under pressure and deception.
Paul also told Timothy that some would depart from the faith by giving their attention to deceiving spiritual influences and false teaching (1 Timothy 4:1). Later, he described people who kept an outward appearance of religion while denying its real power in their lives (2 Timothy 3:1-5). The danger is not only open hostility towards God. It can also be a hollow faith that no longer follows Him.
Now the Spirit speaketh expressly, that in the latter times some shall depart from the faith, giving heed to seducing spirits, and doctrines of devils;
Christians differ on the timing
Faithful Christians agree that Scripture warns of deception and departure from the faith. They do not all agree on whether Paul’s falling away refers to one climactic future event, a pattern that runs through the whole church age, or both. The Bible does not give believers a date chart that settles every question.
Jesus said no one knows the day or hour of His return (Matthew 24:36). That keeps end-times teaching from becoming speculation or fear. The point of these warnings is readiness, not the thrill of predicting headlines.
How to remain steady
A warning about apostasy is also an invitation to hold fast. Paul urged the Thessalonians to stand firm in what they had been taught (2 Thessalonians 2:15). Staying faithful usually looks ordinary: reading Scripture carefully, praying honestly, gathering with mature believers, and refusing teachings that reshape Jesus into someone more convenient.
You do not need to be frightened by every alarming claim. Test spiritual messages rather than accepting them simply because they sound confident or dramatic (1 John 4:1). Keep returning to Christ Himself. He calls His people to endurance, and He is worthy of their trust.
Therefore, brethren, stand fast, and hold the traditions which ye have been taught, whether by word, or our epistle.