Muhammad (peace be upon him - pbuh) was born in Mecca in the year 570 A.D. Since his father died before his birth and his mother shortly afterwards, he was raised by his uncle from the respected tribe of Quraysh. As he grew up, he became known for his truthfulness, honesty, generosity and sincerity, so that he was sought after for his ability to arbitrate in disputes. The historians describe him as calm and meditative. Muhammad (pbuh) was of a deeply religious nature and had long detested the decadence of his pagan society and their practice of worshiping idols.
It became his habit to meditate from time to time in the Cave of Hira near Mecca. At the age of 40, while engaged in a meditative retreat, Muhammad (pbuh) received his first revelation from God through the Angel Gabriel. This revelation, which continued for 23 years is known as the Quran. As soon as he began to recite the words he heard from Gabriel and to preach the truth that God had revealed to him, he and his small group of followers suffered bitter persecution. The Arabs of Mecca, who were among the wealthiest in Arabia, rejected Muhammad's teachings since they perceived Islam to endanger their social stature as it called for equality between all human beings and was eventually going to abolish slavery, which was a common practice in Arabia. They also did not want to give up their idol worship since this was a lucrative business and a source of income to them. They tried to persuade Muhammad (pbuh) to give up his mission by offering money, wealth and position, but Muhammad (pbuh) rejected all of their materialistic offers. What Muhammad (pbuh) wanted was neither wealth nor position, but to be allowed to spread his message among people and call on them to give up their pagan practices, and worship Allah, the God of Abraham, as the one and only God, and to follow His commandments. It is important to point out that the Meccans who were resisting Muhammad (pbuh) never questioned his honesty or integrity, and they kept on entrusting him with their trusts while resisting his message.
Persecution grew so fierce that in the year 622 A.D. God gave the early Muslims the command to emigrate. This event, the Hijra 'migration', in which they left Mecca for the city of Medina, marks the beginning of the Muslim calendar. After several years, the Prophet and his followers were able to return to Mecca and conquered Mecca without shedding a single drop of blood. Muhammad (pbuh) forgave their enemies, destroyed the idols and established Islam definitively. Although, none of the pagan Meccans was forced to embrace Islam, many of them did. Before the Prophet died at the age of 63, the greater part of Arabia was Muslim. Although Muhammad (pbuh) was born to a wealthy family and worked as a successful merchant, he gave his wealth to the poor, and when he died he had less than 5 possessions to his name.
While Muhammad (pbuh) was chosen to deliver the message, he is not considered the "founder" of Islam, since Muslims consider Islam to be the same divine guidance sent to all mankind before Muhammad through prophets and messengers. Muslims believe all the prophets - Adam, Noah, Abraham, Moses, Jesus, etc. - were sent with the same divine guidance for their people. Every prophet was sent to his own people, but Muhammad (pbuh) was sent to mankind at large. Muhammad is the last and final messenger sent to deliver the message of God. Muslims revere and honor him (pbuh) for what he went through and for his dedication, but they do not worship him.
The most fundamental tenet in Islam is that no one but Allah, including Muhammad (pbuh), should be worshiped: "That we worship none but Allah; that we associate no partners with Him" (Quran 3:64). The Quran also emphasized that Muhammad (pbuh) was human, "And they say: "What sort of an apostle is this, who eats food, and walks through the streets?" (Quran 25:7) and that he is no more than a messenger and prophet, "Muhammad is no more than an apostle: many were the apostles that passed away before him. If he died or were slain, will ye then turn back on your heels? If any did turn back on his heels, not the least harm will he do to Allah, but Allah (on the other hand) will swiftly reward those who (serve Him) with gratitude" (Quran 3:144).