Islam is the religion of allegiance to God that began historically with the prophet Muhammad in Arabia in the 7th century. However, according to its own teachings, Islam began as the way of life which God intended for his creation from the start. Human rebellion and sin meant that God constantly sent prophets, including Moses and Jesus, to summon people back to the proper religion.
Muhammad was told to warn his people in the town of Mecca, in current day Saudi Arabia, about the truth of God being spoken through him. A small minority of people accepted him and made up the first small community of Muslims. As a result of persecution, they, with Muhammad, moved to Yathrib in 622. This move to Yathrib, also called Medina, is known as the hijra, and the Muslims who followed Muhammad are known as Muhajirun and those who supported Muhammad in Medina are known as Ansar (the helpers).
Islam means "entering into a condition of peace and security with God through allegiance and surrender to him." This is what Muhammad discovered when, as a young man, in the midst of rival claims about God from the Jews, Christians, and many polytheists in Arabia, he used to go to Mount Hira near Mecca to search for the truth about God. It was here, in a cave on the mountain, that he was overwhelmed with a tremendous sense of God (or his messenger Gabriel) pressing upon him and saying, "Iqra'," "Recite." In other words, "Recite in the name of your Lord who has created, created man from a drop..." These are the first words revealed by God, which were later collected into the Qur'an, the Islamic holy book. Muslims believe the Qur'an is God's actual utterance and has been with him in heaven from eternity. God has sent this utterance as guidance to humankind through successive messengers such as Musa and 'Isa, who each transmitted it to meet the needs of their own people. Finally, God sent the Qur'an in its complete form through the last messenger, Muhammad, who was only a man, exemplary though he was. He was the human channel of God's will.
From the first dramatic moment on Mount Hira, Muhammad was given the all-important understanding that if God is God, there cannot be rival accounts of "who God is," and there certainly cannot be rival gods or many gods. There can only be God, and for that reason he is called Allah, "the one who is God." Neither can there be rival religions or people divided against each other - all people come from God and return to him after death for exact judgement on their actions. All people should, therefore, become a single umma, or community, and every action and aspect of life should bear witness to the fact that "there is no god but God, and Muhammad is his messenger." This witness is the Shahada, the first of the Five Pillars of Islam, the foundations of Muslim life. The Five Pillars give structure and unity to Muslims all over the world.
The Foundations of Life: The Qur'an is the nonnegotiable authority in Muslim life and belief. But it does not cover all circumstances in detail, so the words and actions of Muhammad and his companions are accepted as a living commentary on what the Qur'an means and how it should be applied. They were gathered in six revered collections, the Sahib, meaning "sound," and are known collectively as the Hadith or Sunna, the customary practice of the Prophet. Methods of exegesis or interpretation emerged, particularly that of consensus in the community and the use of analogy, ijma and qiyas. Major traditions then developed that drew up law codes for life, known as Shari'a. There are four major schools of Shari'a, and most Muslims live their lives according to one of them.
Divisions in Islam: After the death of the Prophet Muhammad in 632, the Muslim community split. Those who thought that his successor or caliph should be the best qualified man chose Abu Bakr. They became the Sunni Muslims, those who follow the Sunna or custome of Muhammad. Others, the shi'at 'Ali, thought that his nearest relative, his cousin and son-in-law 'Ali, should succeed him, and they became the Shi'a Muslims. Not much separates the two groups in belief and practice, but Shi'as exalt their Imams, a succession of leaders, whom they regard as a line of inspired teachers. There have also been bitter political divisions.
he Influence of Islam: Within 100 years Islam had swept over the known world, reaching from the Atlantic to the borders of China. It has remained a rapidly expanding religion, with about a quarter of the world's population being Muslims. They form nearly total majorities in countries in the Middle East, northern Africa, parts of central Asia and Indonesia. There are also substantial minorities in the West, in countries such as France, Germany, the UK, and the United States. There is also a substantial population in China.
In its early centuries Islam led the world in the recovery of Greek science and philosophy - words starting with al-, "the," such as "algebra" and "alchemy," the beginning of modern chemistry, are a trace of this.
In another reaction, some drew closer to God, seeking to know his immediate presense. These were the Sufis, a name probably deriving from suf, the rough wool cloak that they wore. This mystical Islam became widespread in the 12th century and has remained influential ever since.