The main message of Islam is monotheism. Belief in monotheism is the cornerstone of the Islamic faith. Muslims believe that all the Prophets sent by God to humanity shared the same central message, and that was the message of monotheism. Monotheism is a term used to refer to the belief in the existence of only one diety (God). Muslims believe that there is only one God who created the universe and everything within it. This one God created the heavens, the earth, the stars, the mountains, the oceans, humans, animals, plants and everything else in existence. Muslims also believe that this one God sustains us by His mercy by continuing to bless us with the essentials of life.