Medieval Christians branded Muhammad a fraud simply because everything he did was religious

Evidence

This probably explains the constant preoccupation with Muhammad’s ‘hypocrisy’. Muhammad became essentially the simulator sanctitatis, although the things he had done were things that Islam, following him, did not believe to be sinful at all. Temptations of the world and the flesh were encouraged by the substitution of a fleshly Paradise for damnation. As Muhammad’s life was understood, it was impossible to suppose that he acted contrary to Christian ethics without knowing what they are. He simply seemed by actions and doctrines alike to oppose Christianity. Enough was known about him for it to be clear that everything he did, he did for religious reasons and with religious motives. The only possible conclusion in those days was that he was a fraud who hid his wicked designs beneath a mask of religion; and the gravity of the matter made it inevitable that this view should always be stressed. — Norman Daniel, Islam and the West, 1491

Categorization

• DEFINE: Explains ‘simulator sanctitatis’ — the simulator of sanctity — the only category medieval Christian thought had for a religious rival whose sincerity could not be doubted.