Another thing about the two sheds – I’ve mentioned this before, I think, so apologies if you’re bored with it – is that even if we can’t know there is no god, we can know other relevant things, such as, that no one has managed to convince us (“us” being atheists) that god exists.
You could say that you don’t really know that because maybe way down deep somewhere you are a little bit convinced. But I don’t think so: being convinced is entangled with being aware of being convinced – being aware of the conviction is part of the conviction. It seems nonsensical to claim you can be convinced of something without being aware of it.
I know that no one has convinced me that god exists. Maybe that knowing is the “good enough” kind of knowing we use for things like knowing we prefer raspberries to cotton candy, or maybe it’s stronger than that, but at any rate “agnostic” doesn’t seem like the right word for it. I wouldn’t just spread my hands and shrug my shoulders and look blank if someone asked me if I’d been successfully convinced that there is a god. I would say no, definitely not; I find the whole idea conspicuously implausible.