Among these proofs:
1. Muhammad (may Allah's blessings and peace be upon him) was raised illiterate, unable to read or write, and remained like that till his death. Among all his people, he was known as being truthful and trustworthy. Before receiving revelation, he had no prior knowledge of Religion or any previously sent Message. He remained like that for his first forty years. Revelation then came to Muhammad with the Koran that we now have between our hands. This Koran mentioned most of the accounts found in the previous scriptures, telling us about these events in the greatest detail as if he witnessed them. These accounts came precisely as they were found in the Torah sent down to Moses and in the Gospel sent down to Jesus. Neither the Jews or Christians were able to belie him regarding anything that he said.
2. Muhammad (may Allah's blessings and peace be upon him) also foretold of everything that would occur to him and his community after him, pertaining to victory, the removal of the tyrannical kingdoms of Chosroes [the royal title for the Zoroastrian kings of Persia] and Caesar, and the establishment of the religion of Islam throughout the earth. These events occurred exactly as Muhammad foretold, as if he was reading the future from an open book.
3. Muhammad (may Allah's blessings and peace be upon him) also brought an Arabic Koran that is the peak of eloquence and clarity. The Koran challenged those eloquent and fluent Arabs of his time, who initially belied him, to bring forth a single chapter like the Koran. The eloquent Arabs of his day were unable to contest this Koran.
Indeed, till our day, none has ever dared to claim that he has been able to compose words that equal-or even approach-the order, grace, beauty, and splendor of this Glorious Koran.
4. The life history of this Noble Prophet was a perfect example of being upright, merciful, compassionate, truthful, brave, generous, distant from all evil character, and ascetic in all worldly matters, while striving solely for the reward of the Hereafter. Moreover, in all his actions and dealings, he was ever mindful and fearful of Allah.
5. Allah instilled great love for Muhammad (may Allah's blessings and peace be upon him) in the hearts of all who believed in and met him. This love reached such a degree that any of his companions would willingly sacrifice his (or her) self, mother or father for him.
Till today, those who believe in Muhammad honor and love him. Anyone of those who believe in him would ransom his own family and wealth to see him, even if but once.