Atheism is irrational.

[Asmodee]

Theists often try to slip it by us as if it's no big deal, but it is a VERY big to change my position from disbelief to a positive assertion, from "don't believe in God" to "deny God".

I didn't say that you are actively denying that go exists. I am implying that you have taken a stance with this respect to the proposition "Does god(s) exist?" You have tacitly expressed that your answer is "No it/they do not." Based on the way you have chosen to make that position known, I have made a personal judgement that you would resist attributing anything to a divine cause.

But this issue isn't just about miracles. Reported miracles are not a cause of faith. No one reads the bible and says, "wow! they recorded miracles, therefore God exists." No, they see them not as evidence; but rather, as instruction. That a miracle occurred is far less important than why it occured. I have no experience with the miraculous. Instead, I see the work of Providence in entirely natural processes.

You kind of just did it there again.  The question isn't, "Does God exist" because that question is unanswerable.  Am I a God?  I know that Ghostbusters taught me to say "yes", but I am not.  And no gods walk openly among us.  So I cannot answer that question.  Nobody can.  The proper question is, "Do you believe god(s) exist?", and THAT is the question to which I answer "no".  I do not believe any gods exist.  Not believing something is not even close to denying that thing.  I don't believe you to be a billionaire, but I'm not making the statement that you definitely are not.  Completely and utterly different.

I don't think many theists actually realize it when they're shifting the language like that to bolster their own beliefs and arguments.  It is, after all, much easier to dislike a person who "denies" your beloved beliefs than it is to dislike one who simply doesn't believe it.  It makes it easier for you to make the "personal judgement" that I would resist "the truth", which takes the sting out of it when I find your argument unconvincing.  Then it's not a problem with your argument, it's a problem with me, exactly as you expected.

Your response about miracles is actually very interesting to me.  On another forum I was recently discussing miracles with a Catholic, who thinks every parlor trick that even his own church won't certify is absolute proof of magic.  Something about blood liquefying.  I actually pointed out to him there there was not a single mention in the Bible of a pointless miracle like goo getting runnier.  Not one.  Without exception, every single display of magic in the Bible had a clear purpose.  The wedding needed wine.  The people needed fed.  The world needed cleansed.  Moses needed to show Pharaoh's magician his cock was bigger.  There is not one instance where God cast a pointless spell just because he could.  And interestingly, there was also not one instance where God cast a spell with the purpose of convincing people that his magic was real.  More powerful, yes, but not "real".  In fact, Jesus actually refused to do that very thing.  So I don't know what the red goo in the bottle is, but I do KNOW it's not blood.  But I don't "know" that because it's what I want to believe.  I know that because I have never seen magic AND the claims they are making simply do not match the past actions of the deity they are attributing it to.

But you are wrong about one thing there.  There has been at least one reported miracle which very much was the "cause of faith", if you take the claims at face value.  It happened on the road to Damascus.