The prophet Muhammad dictated his philosophies which are housed within sacred scripture of the Qur'an (Koran) and the Hadith (collections of Sunnah which supplements the Qur'an).
One of Muhammad's philosophies is each human being is born good and in a state of Islam and throughout their life (or path) they are met with decisions to chose between good and evil. In this context the state of Islam refers to each person is born submissive to God on his terms, in peace.
Another of Muhammad's philosophical teachings is in order to be a faithful follower one must accept and believe all messages of Islam set forth in the Qur'an, Hadith and Shariah (legal interpretations of the Qur'an and the Sunnah). These teachings, or Islamic doctrine, are credited to come from God through Muhammad and are developed from six core beliefs:
1. There is only one God, who is known as Allah.
2. The chief angel is Gabriel who appeared to Muhammad.
3. Muslims (followers of Islam) believe in four books: the Torah of Moses, the Zabur (Book of David), the Injil (Gospel of Jesus) and the Qur'an. The Qur'an is the final word.
4. Muhammad is a prophet, the last and greatest of 28 prophets.
5. On the last day, Allah will judge people and people will be sent to either heaven or hell. Hell will harbor those who oppose Allah and the teachings of the prophet Muhammad.
6. Belief in kismet or one's fate or destiny is determined by Allah.
Lastly, Muhammad believed that his faith, the faith of Islam is open to all people regardless of race, gender, birthplace, or past.
(Ridenour, F. So What's the Difference? p.75-80)