Muhammad was born into a rich family, and grew up to be a manager of the caravan for his future wife. He was a kind man, and put others before himself. When he was forty, he began preaching messages and started the religion Islam. Because Muhammad was a rich man himself, and one of his messages was that the rich should help the poor in a monetary form as well as physical help. That made poor people and more selfless rich people follow Muhammad. The reason that some rich people didn't follow Muhammad is that he said that when people joined the Islamic faith, they would become part of a great community, where rich and poor were equal. Most rich people didn't want to be equal with the poor people that they looked down upon, and so they took a while to become Muslims. But once Muhammad's campain really picked up its pace, and the people of Mecca surrendered to Muhammad and his followers, almost every Arab in Arabia was a Muslim.