Mohammed told us for the hundred times that he's not the one to be worshiped he's an ordinary person but God gave him a miracle ( which is The Holy Quran ) for people to believe what he said .. Jesus peace be upon him had miracles also like every prophet was sent by God over the past centuries … Mohammad knew Quran by heart like I said it was a miracle who wrote it ? every time sth'd revealed by God Mohammed told al-kholafa' al-rashedeen ( the first people who believed in Islam ) to write down what he'd been told since like you said he can't write but you just know half of the information …. About the things you've mentioned below your post …only by hearing' the stoning' thing but some of the girls living at the time of prophet Mohammad got away with it who helped them with that ? the prophet Mohammed him self did God got mad on him ? no why ? cuz FORGIVNESS in Islam is so important much more that anything else and in Quran if you read it u'll notice that it goes in the way of mentioning the sin , the punishment , then GOD IS Forgiving