Atheist (remember to use the -ist and you got it) is someone who states that God does not exist. It is a positive statement of knowledge, a positive faith claim, rather than the absence of knowledge (which is agnosticism). Many atheists say they are not claiming to know, when they are really saying "I know there is no God, and you can't know there is one." Atheists commonly are recognized by their desire to tell you that you are wrong for believing; they have an "evangelical" zeal in this. Agnosticism (often confused with Atheism) stems from the Greek word for knowledge, gnosis. It says you cannot know if there is a God. Within agnosticism there are two main types: "I do not know," and "I cannot know, and you cannot know either." the latter blends into atheism but does not make a faith statement about reality, merely an epistemological statement on the limits of human knowledge.