It is written in following books of religions that God is only one.
Islam: Say: He is Allah, the One and Only. (Holy Quran 112:1)
Hinduism: “Ekam evadvitiyam” “He is One only without a second." (Chandogya Upanishad 6:2:1)
Sikhism: "There exists but one God, who is called The True, The Creator, Free from fear and hate, Immortal, Not begotten, Self-Existent, Great and Compassionate." (Sri Guru Granth Sahib, vol:1, Japuji verse:1)
Zoroastrians (Parsis): "He is one; He is without an origin or end. He has no father or mother, wife or son." (Dasatir, Ahura Mazda. Refer to Yasna 31:7 & 11)
However, there is disagreement among all mankind about true name of God because they do not have true awareness.
In the 21st century of modern science & technology when there are billions of peope with mobile phones in their hands, God demonstrated his great and amazing miracles through Nature which are against the laws of physics. You will never find name of false gods naturally appearing or being called by creatures of Nature because nature only obeys the Command of its creator.