Allah laid this point utterly bare when He said, “They dispute with you about the truth after it has become clear” (8:6). That is: whoever argues about the truth once its reality or the way to act upon it is plain is, in the judgment of both the Law and sound reason, in error.

He also says, “What is wrong with you that you do not eat of that over which Allah’s name has been pronounced, while He has already detailed for you what He has forbidden you?” (6:119). Here He censures them for refusing to eat what has had Allah’s name mentioned over it, and He states the reason for the censure: He has itemized every single thing He has prohibited for His servants; therefore, whatever He has not declared unlawful is manifestly lawful, leaving no room for hesitation.

After citing the verses that prove the obligation of faith, He rebuked those who still hesitated once everything had been clarified: “So what is the matter with them that they do not believe? And when the Quran is recited to them, they do not prostrate” (84:21).

When He set forth the majesty of the Quran—its supremacy over all speech, its peerless clarity, its unrivaled truthfulness, and its matchless benefit—He said, “Then in what statement, after Allah and His signs, will they believe?” (45:6).

When He enumerated His manifest and hidden favors, He said, “Then which of your Lord’s favors will you dispute?” (53:55) and, “Which of your Lord’s favors will you both deny?” (55:13).

And He says, “What, then, is there after the truth except misguidance?” (10:32).

In many other verses He commands him to debate the deniers and to do so in the best manner; but once the truth stands in full clarity and every doubt has been removed, He moves from argumentation to threatening them with the punishments of this world and the next. The verses on this weighty theme are indeed numerous.