The situation becomes more complicated in this case. A person who states conclusively that there is no God is claiming to have absolute knowledge of the entire spectrum of space and time which happens to be an attribute of God called omniscience . So, a person who states conclusively that there is no God is in essence claiming to be God. Thus, the only certainty to be found in this person's claim is that he or she is stating that he or she actually does not exist. The atheistic position thus collapses in self-defeat.
Atheism thus becomes a belief system like any other religion.
So apparently a free-thinking individual cannot actually claim to be free from religion if he is indeed practicing the religion of atheism. That would be a contradiction in terms. Some physics students recently showed, through physics, that the Santa claim cannot be true. The speeds that Santa would need to attain would melt the sleigh and flatten Santa into a blob of organic goo. To say that an atheist is making a positive claim is to bump up against a quirk of semantics.