On his journeys to Palestine and Syria he became acquainted with Jews and Christians and got an imperfect knowledge of their religion and traditions. At that time the Jews and Christians had scattered the ideas of monotheism among the Arabs. Some of the Arabs were tired of worshiping false idols and embraced the faith in one God. One of these men was Mohammed. He became zealous to establish a religion throughout Arabia, to teach and compel men to worship only one God and to recognize himself as His only prophet. He spent many days and nights in the caves of Mount Hira near Mecca in meditation and prayer. His zealous efforts to establish his faith brought a return of the violent convulsion and epileptic fits of earlier days, and his enemies said he was possessed with demons. He started preaching to the ignorant classes of Arabs teaching them that there was only one living God who created heaven and earth and all mankind. In A.D. 610, his fortieth year he claimed to have received a call from the angel Gabriel while in a trance in Mount Hira, directing him to say: "In the name of God." Many times after this first meeting he communicated with Gabriel in these caves and saw many visions. Once when almost discouraged he waited for further enlightenment in visions to qualify him for the duties of his office as prophet--if not to commit suicide--when suddenly Gabriel, at the end of the horizon appeared, saying: "I am Gabriel and thou art Mohammed the prophet of God, fear not." After this assurance he commenced his career as a prophet and founder of a new religion. His doctrines were gathered from three religions, the Jewish, Christian and Arabic. He taught that there is only one Allah--Almighty God, ever-present and working will. Henceforth the revelations came from time to time, sometimes like the sound of a bell conversing with him; at other times Gabriel came down and spoke to him. For the first three years he worked among his family. Kadijah was his first believer. His father-in-law, Abi-Baker, Omar, a young energetic man, his daughter Fatima, his son-in-law Ali and other faithful followers to the number of forty, were the first disciples of this new religion, and were very influential in spreading the same. Then he publicly announced that he had a command from God, and had been given the divine office as prophet and lawgiver. As his notoriety spread, pilgrims flocked to Mecca and he preached to them attacking the idolatry of Mecca. When his enemies demanded a miracle from him, he responded by producing the Koran leaf by leaf as occasion demanded. He provoked persecution; and civil war followed. In A.D. 622 he was forced to flee for his life from Mecca to Medina, a distance of 250 miles. This flight is called Higira, meaning the flight, (July 15, 622) from which the era of Islam begins.