How did the religion of Islam emerge?

The first of the revelations that Allah's Messenger, may Allah bless him and grant him peace, received was the true vision in sleep. Then, seclusion was made beloved to him, so he used to seclude himself in the cave of Hira, worshipping there for a number of nights, until the truth came to him while he was in the cave. The angel Gabriel came to him and said: "Read!" The Prophet, may Allah bless him and grant him peace, replied: "I am not a reader." So the angel squeezed him three times, and each time he would say to him: "Read!" and the Prophet would reply: "I am not a reader." Then, on the third time, he said to him: "Read! In the Name of your Lord who created, created man from a clinging substance. Read! And your Lord is the Most Generous, Who taught by the pen, taught man that which he knew not."