I don't see where a single atheist has ever said "I don't believe in anything". Yet you said that in the very next post, literally five minutes afterwards, in which you were told the true atheist position.
At the age of five, Skagra decided emphatically that God did not exist. This revelation tends to make most people in the universe who have it react in one of two ways - with relief or with despair. Only Skagra responded to it by thinking, 'Wait a second. That means there's a situation vacant.'