picture of a man, boy, or possibly woman with his or her fist in the air in the popular atheist symbol of an A in a circle. Red atheist symbol. Show that you're defiant of religious dogma and can think well enough to know the difference between reality and dilusion. You are a free thinker, you are rational, you are a scientist, you are an individual, you are an atheist, and you are not alone. Atheists unite.