Atheists... why do you believe that God doesn't exist?

[MindForgedManacle]

Fail

Your supposed refutation is unrelated.

Er, how is it unrelated? You said - did you not? - that what one knows cannot be faulty?

This knowledge isn't flawed and has never been refuted. Like I said, you could suggest alternatives that may or may not provide as complete an answer (i'm not aware of any).

I think by saying that you show you don't know what you're talking about on this. If you're treating knowledge as a justified true belief, then you can be wrong about things you "know" under that epistemic model: the Gettier cases. Take the following thought experiment:

A person sees two large barns out in the distance. Given the time of day, the side of the barns the persons sees are dark, so he can't make out much of anything about them aside from their general shape. Unbeknownst to this person, only one of the two objects is an actual barn. One of them is in fact just a large cardboard cutout. Epistemically (under Plato's theory of knowledge), no matter which barn this person looks at, they can say they "know" it's a barn. After all, this belief is held with justification (observation, in this case) such that no matter which barn the person looks at, it seems that they "know" that they're looking at a barn. And yet, if the person is only looking at the cardboard cutout they'd be wrong that he knew it was a barn. And yet, regardless of which one they look at, there appears to be no epistemic difference to the person that allows them to distinguish false knowledge from true knowledge if their means of justification is, unknown to them, faulty.