on a single word brought by Muhammad—peace and blessings be upon him—is invalid from every possible angle. For if he was a truthful Messenger in everything he conveys from Allah, the Mighty and Majestic, then everyone knows that what he brought contradicts the Christians’ religion; therefore, if he is indeed a truthful Messenger, the Christian religion must be false. And if they declare even a single word of what he brought to be false, it necessarily follows that, in their eyes, he is not a truthful emissary conveying from Allah. In that case—whether they say he is a just king, a scholar among scholars, a righteous man among the righteous, or even elevate him to a great saint among the greatest saints—whatever titles and praises they heap upon him, inspired by the dazzling perfections they have seen, his manifest virtues, and his pure law, the moment they reject or even doubt one word of what he brought, they have denied his very claim: that he is the Messenger of Allah and that he delivered this Quran on Allah’s behalf.

Whoever lies when he says, “I am the Messenger of Allah,” is not among the prophets and messengers; and whoever is not among them, his statement carries no authoritative weight whatsoever—he is treated like any ordinary person. If the truth of what such a person says is confirmed by independent evidence, the statement is accepted because his veracity is established from another source, not simply because he said it; but if the soundness of the statement is unknown, it is not accepted.

Thus it is evident that unless the one who affirms a man’s prophethood also affirms that he is truthful in everything he conveys from Allah and is protected from persisting in falsehood—whether through error or deliberate intent—any appeal to his words is unsound.