How a non-Muslim can be certain that the Prophet (peace and blessings be upon him) is a prophet

Question:
A Christian asks, saying: How can I be certain that Muhammad (peace and blessings be upon him) is the last of the prophets, and that what he brought is the religion of truth and is from Allah?

Answer:
Certainty in this is achieved through many matters, among which is the report (peace and blessings be upon him) gave about himself that he is the Seal of the Prophets. Greater than that, and prior to it, is the report of Allah in His great Book. Indeed, whoever believes that he is the Messenger of Allah and that the Book is true, will be certain that he is the Seal of the Prophets, because the Qur'an states that he is the Seal of the Prophets, and because it says: , Allah the Exalted and Majestic said: [Al-Ahzab: 40].
Numerous hadiths have been transmitted from him (peace and blessings be upon him) in which he said: So, whoever believes that he is the Messenger of Allah because of the miracles he presented, and the Qur'an is the greatest miracle, the Qur'an itself is the greatest miracle indicating his truthfulness; because no human being can say anything like it, nor can an unlettered person who neither reads nor write produce it, nor can a writer or a reader produce it, because of the great rulings and hidden news it contains, and because of its perfect eloquence. Perfect eloquence is precision and craftsmanship, and because of its news about the Day of Resurrection and the Hereafter. No one can produce such a thing except one who is truthful and taught by Allah .
Then, the great miracles that occurred through his hands, such as the splitting of the moon, which is among the greatest signs by which Allah distinguished him. Likewise, the water that gushed forth from between his fingers, which was witnessed by hundreds of people and a large gathering of people on multiple occasions. And the blessing in the food for which he made du'a, so that it—though very little—sufficed hundreds of people and a large gathering, whereas it was a small amount that would not suffice even two or three people or the like. Along with other miracles that occurred through his hands (peace and blessings be upon him). So, whoever believes in his prophethood will believe that he is the Seal of the Prophets and believe that the Qur'an is the speech of Allah; because it is the miracle of the Ummah.