Classical reasoning distinguishes demonstration from dialectical argument and persuasive rhetoric. Demonstration draws a necessary conclusion from appropriately certain premises; dialectic may proceed from what a disputant accepts; rhetoric seeks persuasion without always delivering certainty.
The central claim of prophethood needs more than an impressive speech or emotional appeal. The miracle and its evidential connection to truthfulness must be defensible.
Persuading an audience, silencing an opponent and establishing a conclusion beyond reasonable doubt are different achievements.