According to Islam God is One, Eternal and Absolute. He is everything, everything is from Him. God, the Creator of all things is the Sustainer of the Universe.
God: there is no god but Him, the Living, the Eternal One. Neither slumber nor sleep overtakes Him. His is what the heavens and the earth contain. Who can intercede with Him except by His permission? He knows all about the affairs of men at present and in the future. They can grasp only that part of His knowledge, which He wills. His throne is as vast as the heavens and the earth, and the preservation of both does not weary Him. He is the Exalted, the Immense One. (2:255)
Say: ‘God is One, the Eternal God. He begot none, nor was He begotten. None is equal to Him.’ (112: 1-4)
Chapter 112 of the Qur’an, entitled Ikhlas, gives us the essence of monotheism. Not only does it tell us of the oneness of God, but it also makes it clear what the oneness of God means. This chapter presents the concept of God, purified of all human interpolation, for, prior to the advent of Islam, tampering with the sacred text had caused this concept of God to be distorted for all would-be believers. God is not many. He is only one. All depend upon him. He depends on none. He, in his own being, is all-powerful. He is above to beget or begotten. He is such a unique being who has no equal or compeer. All kind of oneness belongs to this Almighty Being. The concept of One God is the actual beginning point and also the only source of Islamic teachings.