I think he is coming from the perspective that "do you believe in god" is not the same as "do you know if god exists"?
This is where the word "believe" is being stressed too much. I mean honestly, doesn't the answer to either of those questions mean the same thing?
Do you know if god exists? "Yes, god exists", "No, god doesn't exists".
Do you believe in god? "Yes, I believe in god", "No, I don't believe in god".
This why it's a play on the word "believe", when that word isn't significant since both the inquirer and the respondent both understand the context of the question. For example, if you are to say, the word believed is being used in the context of the god's philosophies and rules, then that's indeed a different context. In this case, I can know god exists, but don't believe in him (his ideals and whatnot). In the way he described it,"believe" is merely swapping places with the word "know".
So to cap this segment, "believe" can be used in the context of the god's existence, or his doctrines. "Do you know if god exist?" would be in the same context of the former.
Agnostic means that they don't know if god exists- but does that make sense? Because noone can know for 100%. So are we all agnostic?
This is how I see it: the closest an atheist can come to being an agnostic is saying, "there may be a god, but I don't believe in him."
Now, if I were to contrast that with an agnostic, it'd be, "there may be a god, but I don't know whether to believe in him or not."
Most atheist I know of outright say that there is no god (I actually haven't come across many atheists that says there "could be" a god), likening him to a fairy tale (especially when making jokes). An agnostic, normally, wouldn't do such a thing. There seems to be a clear difference in belief between an agnostic and atheist, which is why I think that close-ended question doesn't do it justice.
Oh yeah, I reaaally want to stress that when an atheists states "of course we can't prove god doesn't exists" isn't the same when an agnostic says "there could be a god". In the mind of the atheists, that's just a response to a ridiculous "prove it!" demand. They say that because they have to, it'd be foolish of them to think they can disprove god's existence. In the mind of the agnostic, they seriously consider the idea of there being a god out there. So, what is seen as identical (i.e. there's no difference between an atheist and an agnostic's belief), is actually relation, but not the same on the basis of an agnostic actually giving legitimacy to the existence of a god. They (Well "we" - since I'm an agnostic as well) don't think of it as, "well there could be unicorns too". I think the
relation is why you and Cornson see them as the
same.
Actually, we can't know anything about a god- except what's written in holy books, but then you have to believe it is the word of god. And that's not proof: "the holy book is god's work so he exists so it's his word." I'm sure you know about this fallacious reasoning. We may have definitions of god- but proving god's existence based on the definition is tautology- and that's no proof again.
Yes, circular reasoning, not too long ago I informed some relatives of mine of that very same fallacious reasoning when they were trying to argue with me that god is real and kept using bible quotes to do so

.
I'm also sure you know the argument: 'we are all atheists to some extent, when it comes to gods like Thor, Zeus, Amaterasu etc'. Semantically that statement may not be accurate, but the reasoning is legit, at least I accept it as legit (which leads to the question what evidences and arguments are sufficient for someone to accept- it's very subjective). I can come up with an infinite number of gods- now if 99.9999....infinitum (%) of them don't exist, as I know they are just made up, as for that one monotheistic god to exist, I can be 99.999...% certain it's just as fake. But there is always a chance of being wrong. I think that slight chance is what is filled in with faith.
I agree that the reasoning is legit.
Actually, at least for me, the fact there are so many "gods" is also a facet instilled into an agnostic's uncertainty. It makes it that much harder to accept since everyone is so sure that their god is real and even give anecdotes of some kind of spiritual event. Of course, there could be many gods. And I think you'll find some dictionaries out there who define it as simply ""uncertainty in the existence of a higher power or the metaphysical". This would cover any god, and I think this more accurately describe an agnostic.
There is no direct proof of god- only logical assumptions. That is not ample 'proof' to me. I'd also use the argument that if something doesn't exist- it indeed can't be either proved or disproved. But if it does exist, there must be a way to verify that. However, scientific methods may not be applicable to god- so we'll never know. Personally I see no point in believeing as god doesn't affect my life either way.
I agree that there is no proof of god, or at least none has been offered or manifested itself.
Affect my life - I wonder about that. Of course, this is all very personal. Though I guess we all have our reasons for our particular interests.