Islam is the way of life for those who believe in God and want to live a life in worship and obedience to none but God. The reward is forgiveness from God and an everlasting life in the Heaven.
Belief in one God, Allah in Arabic, constitutes the very foundation of Islam. There is no deity except Allah. He is indivisible and absolutely transcendent. God is the Almighty, the Creator and the Sustainer of the universe, Who is similar to nothing and nothing is comparable to Him. Worship and obedience belongs to Allah and Allah alone. Joining other gods with God is an unforgivable sin. Any one who joins other gods with God has strayed far, far away from the Truth.
Prophet Muhammad was born in Makkah, a city in the present-day Saudi Arabia in 570 C.E. He is a direct descendant of Prophet Ishmael, the first son of Prophet Abraham. Peace and blessings of God be on all His prophets. Muhammad received divine revelations (The Holy Quran) over a period of 23 years in the seventh century of the Christian Era. Muslims believe that he is the last Messenger sent by God for the guidance of mankind until the Day of Judgment. He is the model for humanity of all walks of life to follow until the Last Hour. God sent him as a mercy for the worlds.
The primary sources of knowledge are the Holy Quran and the Sunnah of the Prophet Muhammad. Anyone wanting to live a life in worship and obedience to God should follow these teachings.
The Holy Quran (also written as Koran) is the Divine Book revealed to Muhammad (peace be on him). The Holy Quran confirms what was revealed to earlier messengers of God and serves as the Criterion of right and wrong. The Quran is the only divine Book extant in its original text and is therefore the only source of Guidance from God for all mankind.
The Sunnah of the Prophet Muhammad refers to his sayings and actions, his approvals and disapprovals. The Sunnah is collected in books separate from the Holy Quran and are known as Hadith books. While the Holy Quran is 100% word of God revealed to the Prophet, not every Hadith is authentic. Early Muslim scholars have classified hadith into various categories ranging from different levels of authenticity to false hadith.