You're the one with a belief based on nothing.
Why do theists have to bring atheists down to their level with this "belief" business? A true atheist doesn't have to "believe" in anything...in fact he does the opposite...he refuses to believe in the notion of a being that has no evidence of existing or being in power.
Here's the definition of Atheism on Wikipedia: Atheism, as an explicit position, can be either the affirmation of the nonexistence of gods, or the rejection of theism. It is alsodefined more broadly as synonymous with any form of nontheism, including the simple absence of belief in deities.