This is a good point, and it depends on the view of atheism. If one takes the view that the atheist says, “I know God doesn’t exist,” in the same way that many (most?) theists, say, “I know that God exists”, then the atheist is an idiot, and so is the theist. By that definition of atheism, and the theistic corollary, all atheists and theists are actually agnostic.
I would generally agree to this. I believe that God revealing Himself, beyond any shadow of a doubt, effectively strips the human being of his free will. So I think that all theists are actually saying amounts to: “I am convinced of God”, “I have experienced God”, “If God does not exist, I do not understand my experience”.
The “atheist” could say the inverse: “I am not convinced of God”, “I have not experienced God”, “If God does exist, I do not understand my experience”.
These are wildly divergent agnosticisms, but they are agnosticisms.
Nobody can know that God exists; nobody can know he doesn’t. All you can do is take either an evidential (scientific) view or a philosophical (supernatural) view. In my opinion, the scientific view carries far more weight because (properly held) it makes no assumptions in the absence of observable evidence.
But this is true of all skepticism. But why draw the line at “observable” evidence? Our senses may be deceived; indeed, they often are. The problem is: what assumptions are acceptable? The empiricist assumes that things that cannot be observed are not true – but this leaves him the troubling problem of how mathematics are true. The rationalist assumes that the most reliable truths can be determined without any evidence (
a priori reasoning) – but we cannot justify
a priori reasoning with reference to itself nor anything other than itself. We have no way to choose which assumptions are best - the empiricist’s or the rationalist’s.
Pascal says, “The heart has its reasons, which the reason knows nothing of.” Perhaps belief in God isn’t a head decision, but a heart decision. That is another assumption, I know, but I am willing to stake my life on it.