Islam started when the prophet Muhammad was born, and it was formally formed in 622 A.D. throughout the Arabian peninsula. The religion has more than 1.5 billion followers in the world who all pray to Allah using the sacred text, the Qur'an.
Muhammad was believed to be one of God's prophets along with Jesus and Moses. Muslims believed that Muhammad could share God's word with them through God's revelations to Muhammad. However, other people did not believe that Muhammad was a prophet and thus Islam was organically created as these followers separated themselves from Christians and Jews. It is said that Muhammad started hearing divine voices and receiving visions when he was in his forties, and it is these voices and visions that became the core of the Holy Book, the Qur'an, says the Metropolitan Museum.