Its title, "the criterion" (between truth and falsehood), sets the tone: a defense of the Quran's authenticity against Meccan accusations that it was invented, borrowed from earlier scriptures, or dictated by others to Muhammad. It answers specific taunts — that a "real" prophet should be wealthy, or accompanied by angels — with the reminder that earlier prophets were ordinary people too. It vividly describes the regret of the wrongdoer on judgment day, biting his own hands in remorse for having followed a misleading companion rather than the messenger — a striking image of peer influence taken to its worst conclusion. It describes the qualities of "the servants of the Most Merciful" in a concluding passage — walking humbly, responding to ignorance with peace, spending moderately without extravagance or stinginess — offering a compact character sketch of the ideal believer near the surah's close.
Directly answers skeptics' objections (why isn't the prophet rich? why no angels?) — a template for responding to doubt with reasoned argument rather than dismissal. That image of belated regret over bad companionship is frequently invoked in discussions about the influence of social circles on personal choices, framed as a warning relevant well beyond its original audience. That closing character sketch is frequently used in religious education as a standalone checklist for personal conduct, independent of the surah's earlier arguments against Meccan skepticism.