Ok, well I will humor you. If atheism is to be thought of as a belief system as religionists like to think then its the confirmation of two philosophies Rationalism (reason) and Empiricism (evidence) and in simple terms its the method of only accepting valid as well as reliable reason and evidence.

Since god hypothesis claims fail to substantiate with any “evidence” as well as are exposed to contain thinking errors, logical fallacies and internal contradictions it has no warrant nor justification to support “reason” believing it to be in anyway true.

Thus, to your belief that Atheism is a belief but you have it backwards, we have credible belief systems that lead us to the conclusion of Atheism which is stating I do not have a belief in gods, which because of the facts in evidence is the only rational choice.