Thus a person who believes in the Oneness of the Creator and Sustainer of the universe has to worship Him alone and refrain from associating any partner with Him of any sort whatsoever. All the prophets asked their people to submit themselves to Allah alone. Allah Almighty said, "That is Allah, your Lord!. There is no god but He, the Creator of all things. Then worship Him, and He has power to dispose of all affairs." (19) He, the Almighty has also stated in the Holy Quran "If indeed, you ask them who is it that created the heavens and the earth, they would be sure to say, 'Allah'. Say : See you then the things that you invoke besides Allah? Can they, if Allah wills some penalty for me, remove His penalty ? Or if He will some grace for me, can they keep back His grace ?" (20) This acknowledgment of Allah's unity as the only Cherisher and Sustainer of the universe is deeply rooted in the nature of mankind No one disputes it. Even idolaters admit this fact. No one is known among the various sects of the world to have negated this fact except the atheists, who believe in the materialistic doctrine. They say that the world proceeds by itself without anyone to rule or regulate its affairs. Allah the Almighty has said, "And they (the atheists) say : What is there but our life in this world ? We shall die and we live, and nothing but time can destory us." So Allah said to them, "But of that they have no knowledge : they merely conjecture" (21) It is evident that their denial of Allah is based on a mere assumption and they have no proof. Hypothetical conclusions do not help in guiding to the right path. Therefore, they had no answer to the word of Allah. Allah said, "Were they created of nothing, or were they themselves the creators ? or did they create the heavens and the earth ? No, they have no firm belief." (22)

They also have no answer for the statement of Allah, the Almighty in the Holy Quran "Such is the creation of Allah : Now show Me what is there that others besides Him have created." (23) "Say : Do you see what it is you invoke besides Allah ? Show me what it is they created on earth, or have they a share in the heavens?" (24) Those who pretend to deny this unity of Allah in fact confess it in their hearts as Pharoah did. Allah Almighty said, "Moses said to Pharoah, "You know well that these things have been sent down by none but the Lord of the heavens and the earth." (25) Allah, the Almighty stated also about Pharoah and his people "And they rejected those signs in iniquity and arrogance , though their souls were convinced there of." (26)

He, the Almighty said about previous nations : "Remember, also, the Ad and the Thamud (people) Clearly will appear to you from (the traces) of their buildings (their fate) Satan made their deeds alluring to them and kept them back from the path, though they were gifted with the intelligence and skill." (27)

Thus we notice that there has never been any group denying the Oneness of Allah in the sense that He alone is the Creator and Sustainer of the universe.

Magians (adherents of Mazdaism) believe in two gods, light as creator of virtue and darkness as creator of vice. They believe that the original one is light and darkness is casual resulting of it, and that light is superior to darkness.