To see is to know.
When you "believe" something it means that you don't know whether it exists or not. In my opinion it's foolish to believe because it means that you can't prove that it's there. In other words, it's equally stupid to believe in God as it is to believe in little midgets that steal your underwear. Unfortunately not many people are smart enough to understand the inconsistency in their beliefs.
If you want to read about this I suggest you google "Russel's Teapot".
http://en.wikipedia.org/wiki/Russell%27s_teapot