Verse explainer
Paul's warning isn't a prophecy schedule — it's a pastor telling anxious believers: don't be stampeded by anyone claiming the end is already here.
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;
BSBLet no one deceive you in any way, for it will not come until the rebellion occurs and the man of lawlessness—the son of destruction—is revealed.
The plain meaning
The Thessalonians had been rattled by a report — a supposed letter, word, or prophecy — claiming the Day of the Lord had already come (v. 2). Paul's response is pastoral before it is prophetic: stop letting people panic you. His argument is simple: certain things haven't happened yet, so that day isn't here. Two markers must precede it — a great 'falling away' (Greek: apostasia, a mass defection or rebellion) and the unveiling of 'the man of sin, the son of perdition.' Neither marker, Paul implies, has yet appeared in full. The identity of 'the man of sin' has been argued across centuries — some commentators see it pointing toward a Roman figure, others toward a long succession of anti-Christian power centered in Rome, others toward a still-future individual. What is not in dispute is the pastoral logic: Paul is not handing out a detailed end-times chart. He is telling believers under pressure not to abandon their posts or their reason. The deception he fears most is the kind that makes people panic, stop working (see 3:10-12), and suspend judgment — which is exactly what bad eschatology has always done.
The common misreading
What the commentators say
Henry reads the 'falling away' as a general religious apostasy — not a civil revolt — gradually overtaking the church and giving rise to antichrist. He applies 'the man of sin' and 'son of perdition' most naturally to the papal system: notorious for advancing its own authority above God's, promoting error, and causing the destruction of souls. Yet Henry's emphasis stays pastoral: Paul's chief point is that the Thessalonians were being deceived, and the surest guard against that is knowing what must come first.
Clarke stresses that 'apostasy' means a fundamental corruption of Christian doctrine rendering it 'completely inefficient to salvation' — not mere moral laxity but doctrinal collapse. He notes that the Hebrew equivalents of 'man of sin' and 'son of perdition' were rabbinic titles for the devil and for Adam after the fall, pointing to someone who embodies iniquity and carries others into ruin. He leaves the precise referent open, treating it as one of Scripture's genuinely difficult prophecies.
JFB draw a sharp parallel: as Christ was first hidden in mystery then openly revealed, so the 'man of sin' works secretly before his full disclosure. They connect 'the apostasy' and 'son of perdition' to Daniel's willful king who exalts himself above every god (Dan 11:36). While they see Romanism as a major historical instance of the mystery of iniquity at work, they hold that its full, final concentration in one individual is still future — the abstract precedes the concrete.
The word behind it
Transliterated directly into English as 'apostasy.' From apo ('away from') + histēmi ('to stand'): a standing away, a defection or rebellion. The KJV renders it 'falling away'; the BSB 'the rebellion.' Both are defensible — the word can mean religious defection or active revolt. The choice between 'falling away' (passive drift) and 'rebellion' (active rejection) significantly colors how readers imagine what precedes the end, which is precisely why the Greek term is worth knowing.
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