The religion of Islam began in the 7th century when the prophet Muhammad received revelations from God and wrote them down in a book that would come to be called the Qur'an. Muhammad began teaching what he had learned from God, and the community began to follow him because he led by example from what he believed he had learned.
Muhammad was the founding father of Islam. He was the original Muslim and began teaching what God had taught to him in the cities of Mecca and Medina. These cities are located in what is now known as Saudi Arabia in the modern world. Muhammad began writing down everything he had learned from God and recorded it in a book called the Qur'an. This book has been translated and passed down over the centuries, but only books translated in the original Arabic language are considered to be authentic.
Despite Islam being a more modern religion than others, it is the single fastest-growing religion in the world. By 2025, it is expected that there will be over 3 billion Muslims around the globe. It differs from Christianity in that Muslims believe in Allah and there are no deviations of God such as Jesus or the Holy Spirit.