This will be a short post, because I don't have a lot of commentary to offer. I just want to set the record straight on this one issue. We can begin by defining some terms.
I make no distinction between "faith" and "blind faith." In order for the word to have any meaning at all, it must be distinguished from knowledge or fact. Therefore, faith is defined as belief in a proposition without sufficient evidence to justify that belief. To myself, that defines it right out of any sort of validity as a valid way of knowing, and I don't believe faith is a valid way to arrive at any conclusion. However, Christians should not disagree with this definition, because their religion has as a fairly central dogma that faith--as I've defined it--is a virtue. "Blessed are they who have not seen, and yet have believed." -John 20:29
Atheism is not necessarily an active disbelief in a god or gods. Atheists do not, by necessity, claim any absolute knowledge regarding the existence of a deity. Indeed, many claim no knowledge at all. All that atheism requires is a lack of a belief. There is a distinction between active disbelief and passive disbelief. Atheism can include both, but only requires passive disbelief.
Anti-theism, or strong atheism, is a distinction marked by precisely that movement into active disbelief. So while the atheist says "I don't believe in gods," the anti-theist says "I believe there are no gods." Understand the difference? Good.
Now, the burden of proof for any proposition lies upon the party making a positive claim. Theists make a positive claim that there is a deity. So the atheist doesn't have a burden of proof to claim there is no god. All the atheist needs to do is come to the conclusion that the theist has not met his burden of proof.
We've all seen the "evidence" Christians like to produce for their claims. Anyone with even one neuron can tell they fail to meet their burden of proof. This is why their beliefs are faith-based. They believe in the absence of evidence. Because the atheist does not accept this blind faith-based form of arriving at "truth," and does not accept that the theist's burden of proof has been met, he does not accept their conclusions--he does not believe in gods.
Because this sort of philosophy related to evidence and the burden of proof is so akin to the scientific method, we can treat them as essentially the same. We realize that in science, no claims are ever proved--they are only accepted to degrees of certainty. We also realize that things for which we currently have no evidence could possibly be true, and that if this is the case, there should be some evidence out there somewhere that would potentially justify these claims. But we do not accept the claims until that evidence comes in. So the scientific position and the atheist position are one and the same:
1) We require evidence for our beliefs.
2) There is currently no evidence in favor of the existence of a deity.
3) Therefore, we TENTATIVELY reject theistic claims.
The anti-theist goes farther than that, though. The anti-theist takes the position that "there is no god." Rather than passive disbelief, he engages in active disbelief--he actively believes there is no god. As this is a positive claim, he does have a burden of proof that needs to be met.
Can that burden of proof be met? Sure, but that comes with qualifications. There is no such thing as absolute proof nor is there such a thing as absolute disproof. Science deals with degrees of certainty--often very strong degrees of certainty--but we never call it "proof." It is generally considered to be impossible to prove a negative, anyway. So how can the anti-theist meet his burden of proof? By using the scientific method.
There's an old adage that says absence of evidence is not evidence of absence. Meaning, just because there's no evidence for something doesn't mean that something doesn't exist. Well, strictly that's true, but in practice, when we apply the scientific method to some question, we are narrowing down possibilities. We determine what experimental outcome would be true if our hypothesis is correct, and after running the experiment, we see if our hypothetical predictions have been fulfilled.
In the case of gods, we can look at the existence of god as a hypothesis and come up with testable predictions. For instance, we might say, if a god exists, we should expect people who are prayed for to recover from disease more quickly than those who are not. Or we could come up with any number of other testable predictions. You'll note that since we cannot test for a supernatural being directly, we must test for the RESULTS of that being's existence. Do we come up with absolute proof? Never! But can the anti-theist meet a reasonable burden of proof for his position through this sort of thought and experimentation? We must all admit that this is at least possible. Whether or not the anti-theists actually HAVE met their burden of proof is a much larger topic, and one for another paper.
So, theists require faith because they believe in these propositions without any evidence to justify their claims.
Atheists do not require faith because they don't even make any claims at all! They just reject the theists' claims.
Anti-theists also do not necessarily require faith, IF you grant that they meet a reasonable burden of proof for whatever claims they make.
It is extremely easy to just make something up and then claim it require faith to deny, but that's not the way things are done. It doesn't require any faith to disbelieve claims that an invisible dragon lives in my garage, or that there are faeries at the bottom of the garden. Disbelief does not require faith. In some cases, it may require ignorance, as is the case with the Holocaust deniers (they are ignorant of history, but they don't have "faith" that the Holocaust never happened) or similar groups of crazies. But it does not require faith. Faith is the unique domain of the believers.
Make sense now?