Most people who say they "know" God doesn't exist are pretenders. They don't really know. And all philosophical proofs against God have turned out to be silly. If you are trying to reason about God, you are already a fake. You are just manipulating symbols in your head and you know it. You have no direct way to proof nonexistence and are just hoping it isn't true. That is why faux skeptics must intimidate and threaten others not to believe. They are really trying to convince themselves. You don't have to intimidate someone into disbelieving the grass is green, because he has direct experience. The real religious fanatics are those who argue that there is no God.
“The greatest burden a child must bear is the unlived life of its parents.”
Carl Jung