//Remember, if you reject what I say, at least have the decency to replace it with your own theory.//
You keep saying this, theland, but it doesn't make sense. As I said before... if I told you my car was broken into, and it was done by a unicorn... you would be able to rule out my theory, even if you didn't actually know the right answer.
It doesn't make sense to cling onto an irrational answer and claim it to be true, just because you can't think of anything better.
Atheists aren't claiming they know, so you can't turn the question around, it is only you making the claims, so up to you to prove them.