Mohammed was a pious man who regularly journeyed to the mountains surrounding Mecca to meditate. His parents died when Mohammed was a young child and he was raised by his uncle. His uncle was a prosperous merchant and Mohammed began working for him (nicknamed al-Amin "the reliable") when he was old enough. He started driving caravans along the trade routes. It was on these treks that he encountered Christians and Jews and learned about their faiths.
When Mohammed was 24 years old he married a widow named Khadijah. He lived in Mecca with his wife and became a prosperous merchant himself. Although he loved Mecca, he disagreed with many of the beliefs and practices held by the citizens and he worked to improve his community.
In 610CE, while meditating on Mount Hira, Mohammed was visited by the Angel Gabriel (Jibreel). Over a period of 23 years Mohammed received these revelations from the Angel and accepted them as the word of Allah. Mohammed memorized these revelations and told them to his best friend Abu Bakr. Abu wrote these revelations down and those writings became the Koran (Qur'an) the sacred writings of Islam. Gabriel informed Mohammed that he was to be the definitive prophet of Allah and that he would be responsible for transmitting to the world the true and complete will of the Creator. Gabriel went on to explain that Allah was the God of the Jews and Christians. These two groups were approached, through Abraham, Jesus and the other prophets, but had misinterpreted some of His messages. Mohammed was called upon to clarify those misunderstandings and unite all of the people under Allah.