god is a being or spirit worshipped as a deity. he is considered to be the creator of the universe in some religions. theists believe that god created everything that exists and has ever existed. some theists think god is immortal (cannot die) and has power without limits. deism is the belief that god exists, but god does not very often change or never changes things in the universe. pantheism is the belief that the universe "is" god, while atheism is the belief that there are no deities. agnostics think we cannot know for sure whether god or gods exist, but still might (or might not) believe at least one deity exists. people who believe that the word "god" should be defined before taking a theological position are ignostic.