Why do people speak of god as though he is a person?

The defenition of god is a supernatural being conceived as the perfect and omnipotent and omniscient originator and ruler of the universe; the object of worship. God is not one man. God can be anything that is worshipped. Why do people think there is only one god? When you thank god or swear to god, what god are you refering to? A god is an object. Not a being.