This proof is found in the Islamic traditions and it says that Hisham bin Hakam asked Imam Jafar Sadiq (AS), “what proof do we have that God is One and alone?” The Imam answered, “The perfect harmony of the creations in this universe is itself a proof of God’s Oneness. God Himself says, “Had there been another creator the world would have been destroyed. (1)
In another Hadith of Al Kafi Shaykh Kuleni has reported Hisham bin Hakam to have said, “ Imam Jafar Sadiq replied to a disbelieving atheist , “ When we find this universe in perfect harmony and arrangement , find the boats sailing then we feel that there is a system in place here. The sun and moon are in orbit night and day and when we see all this and their interdependence and coexistence we understand that there is some one arranging and controlling them. (2)