Islam is a monotheistic religion. It teaches that there is only one God who is the origin and creator of the universe. This is the foundation of Islam, and is reflected in the famous sentence which says that, "There is no god but Allah." (Allah is the Arabic name of God.)
The belief in God relates us to our origin and guides us throughout our life. The belief in one God shows that man should not worship any material thing or person in this universe.
By teaching that there is only One God for all humans, Islam promotes the sense of brotherhood and equality in human society--all are equally related to God in the same way. The Qur'an, the holy book of Islam, says:
He (God) is One, God is Eternal;
He has neither begotten,
nor has He been begotten;
and there is no one equal to Him.