In the creation of the heavens and the earths there are signs for those who think, who ponder, who use their head. The sky above us is standing without any pillars and there is no error in it. It seems and appears perfect. Look up again at the sky and eye return back as there is no error found in its creation.
The sun and moon, the day and night, and the repetition of different seasons one after other shows that there exists a tight control and harmony among the creations. Muslims use Arabic word Allah for God because the Arabic word ALLAH cannot be manipulated like the word God such as God man God father, God mother and Tin God.
If there had been more than one God in the world, the system of life would have destroyed because each God may come forward to prefer his will on the other God. One may order sun to rise and the other may order sun to set similarly the moon and the motion of earth would have disturbed.