In order for a statement about the world to be "philosophically" meaningful, it must also be epistemically available: it must not only describe the world in a semantically meaningful way, I have to be able, at least in principle, to know whether it's true or false. A statement that's unknowable in principle is a statement I don't care about, it's a statement I can't care about; it's a statement that's irrational to care about. "Apathetic" is just too weak a word to capture the radical and absolute character of my not caring.
Like our ninja hiding in the bedroom, many people define "God" as epistemically unavailable, at least to a naturalistic empirical epistemology. Note that any extraordinary, paranormal, non-material characteristics of "God" are not immediately relevant: even an entirely prosaic statement can be epistemically unavailable. The naturalist's rejection of such conceptions of God is based not on the extraordinary characteristics of God, but rather on the concepts' epistemic unavailability: we reject the idea on other grounds before we even get to the extraordinary parts.
A commenter alludes to such a conception of God:
A point that most atheists miss is the self-insufficiency of human reason to attain to a true knowledge of God. Scripture puts it this way, "Who has believed our report, to whom is the arm of the Lord revealed?". Self-sufficiency engenders pride -- the primary sin of man. God reveals himself to those whose hearts seek him in sincerity and self-insufficiency. The truth that really counts is not just rawly empirical and accessible to a self-sufficient human intellect -- it is fundamentally personal, and attained by humility.I'm not precisely sure what this comment means*, but it's clear that the comment references some conception of God that is empirically unknowable.
*I don't expect comments to be rigorously precise.
As we have seen earlier, just that we can construct meaningful unknowable statements is not by itself an objection to an epistemic system. So long as one can plausibly invoke radical apathy, so long as the limits of an epistemic system are exactly equivalent to the limits of our concern, our epistemic system by definition fails to deliver only the knowledge we do not want.
I am not so philosophically naive or foolish as to assert that I am certain that empirical epistemology is the only way of knowing. I can be best characterized as a weak metaphysical naturalist: empirical scientific epistemology is the only way of knowing that I presently understand; it is the only method that does the job I expect of an epistemic method. Therefore, one can draw the accurate conclusion that I hold a more abstract metaphysical principle: an epistemic method has to do a particular job.
There are many different aspects of the job I want an epistemology to do, but an important component is to deliver surprising consistency. I want to be surprised by my knowledge, and I want my surprising knowledge to be consistent with the knowledge I conclude that other people have. I don't want my "knowledge" to be by definition just an expansion or elaboration of ideas I already have, and I don't want my knowledge to be fundamentally idiosyncratic, indistinguishable from personal preference.
It's one thing to say, "I prefer to believe a God exists." That seems like an odd sort of thing to have a preference about, and seems to do some violence to our notions of what a clause such as "a God exists" means and how we should evaluate it, but a preference is a preference: It's a fact about one's mind, and stating the preference is (usually) sufficient evidence that the preference actually exists: it is a real property of a real mind.
But stating a preference as a preference by definition excludes the argument that people with differing preferences are mistaken: preferences can be good, bad or neutral, but they cannot be correct or incorrect. And the comment suggests that people who do not believe a God exists are indeed mistaken: according to the comment, most atheists miss the point, which suggests a mistake (at least somewhere), not a differing preference.
The comment clearly does not assert that atheists are empirically mistaken: whatever point we are missing, we are not missing any empirical evidence, nor are we drawing unreasonable conclusions from the evidence. The comment suggests, rather, that we are missing an alternative epistemology, having something to do with sincerity, humility and the assumption of self-insufficiency.
I cannot draw any strong conclusions about any details of an alternative epistemic system the commenter himself would specify, but I've investigated revelation as an epistemology pretty thoroughly, and I've come to the conclusion that it does not do the job I expect of an epistemic system.
First, revelation shows precisely the inconsistency we would expect of natural ethical intuition being prosaically transmitted and adapted to the individual and cultural requirements of specific times, places and people. Revelation does not show the surprising consistency of scientific statements, which appear much more resistant to cultural and idiosyncratic differences. You might not like nuclear weapons, but few will deny that if you slap enough plutonium together hard enough, you get a hell of a bang; and fewer will say that we can eliminate nuclear weapons by believing they don't physically work.
We have Mohammed's revelation, Paul's revelation, Moses' revelation, Buddha's, Confucius', Joseph Smith's, L. Ron Hubbard's, Mary Baker Eddy's, etc.: all are different, and the differences all correspond closely to the cultural and individual context of the different revelations. Revelation does not appear to establish the sort of consistency I demand of an epistemic system.
And, of course, I myself definitely believe no God exists: why isn't my "revelation" as authoritative as another's?
The commenter mentions sincerity, humility and "self-insufficiency". I don't really know what he means by "self-insufficiency", but I think I'm as sincere and humble as the next guy. But I am missing the point in some sense: presumably because I have concluded that no God exists, I am insufficiently sincere or humble, or I'm doing something else wrong. But if we can tell whether some epistemic system is being "properly" used by evaluating its conclusions according to a priori standards, then by definition it is not delivering surprising knowledge: it can by definition deliver only what is already believed a priori.
Contrast this with scientific epistemology. If someone concludes that the empirical evidence supports Intelligent Design, that's a pretty blatant clue that they're not using scientific epistemology correctly. However, that's just a clue: I can actually show that they're not using scientific epistemology correctly by examining their methodology directly, without using the content of their conclusion as evidence.
The theist has two barriers to overcome, an epistemological barrier and a meta-epistemological barrier. He cannot simply define God to be unknowable: An unknowable God is precisely the sort of God it's positively irrational to care about. I no more care whether or not there's an unknowable God than I care whether the world is run by selfish, greedy, shortsighted and incompetent politicians and selfish, greedy, shortsighted and clever capitalists, or whether it's run by a massive and preternaturally clever conspiracy perfectly simulating a world run by idiots and assholes.
To bring questions about God back into the domain of of concern, the theist must either make an empirical case (which fails dramatically given the actual empirical evidence) or privilege an alternative epistemic system. But an alternative epistemic system must do the job of an epistemic system, by delivering surprising consistency. (The theist could, of course, deny this meta-epistemology and say that an epistemic system need not deliver surprising consistency, but at this point we're getting so deeply enmeshed in layers of abstraction that I'm back to radical apathy.)