You're describing it with a noun, so apparently whatever you mean by "God" is a thing, yes.
I know the thread has moved on a fair amount, but I've been traveling and haven't had a chance to post, and I'd like to come back to this for a moment.
I think it's an error to conflate grammatical categories with ontological ones. The word "God" in English is a noun, but it would be an oversimplification to think that this dictates the range of philosophical or theological meanings that the word could take on. The context of my comment that God is not a thing was in relation to the analogy to a unicorn, and to give a traditional example, the Christian scriptures say that "God is love", and the word "God" is certainly a noun and the subject of the sentence, but love is not a "thing", philosophically speaking, in the same way that a unicorn is. By "thing" I meant an entity for which the predicate "existence" may be understood in the sense that -- were unicorns to exist -- I could refer to
that unicorn, a demonstration that involves a referent in a specific spatiotemporal location with specific physical properties. But much of traditional theology (in more than one religion) asserts that the Divine is not such an entity, and if the predicate "x exists" is taken to mean exclusively such a
thatness, then God does not "exist". I could cite Hindu, Buddhist, and Christian texts on this point.
To go back to the grammatical approach, if I were to try to describe the Divine in linguistic categories, I would suggest that it is adjectival. "Divine" is an attempt to describe a particular experience of life and of reality. As such an attempt it alludes to and incorporates the rich symbolism and meaning of a great many religious practices, traditions, and myths, but without necessarily absolutizing the truth of any particular myth, or any particular language and culture.
If you're using the term "God" in a meaningful way, then you ought to be able to explain what you mean when you use it.
There's been a good deal of subsequent discussion about the possible meaning and value of mystical language, the idea of the ineffable, and the definition of the Divine. I think some of the objections might be clarified somewhat by a somewhat longer section from one of my favorite books, on the apophatic and mystical character of theology:
"An apophatic feature is different from an unknown aspect. Any object of knowledge has an unknown aspect, since no human knowledge can claim to exhaust its object. We do not have exhaustive knowledge of anything. We do not know all the properties of a triangle or the complete nature of a stone or the total beauty of a symphony, let alone the nature of Man, God, or Reality. There are, furthermore, things we simply do not know. Although we cannot say without contradiction, "I understand that I do not understand," we can say, "I am aware that I do not understand." The field of awareness is broader than the field of understanding. Apophatism lies on those fringes of consciousness. Apophatism is aware of the un-said and does not say it. Silence is also a language. Although it says nothing, we are aware of the "nothingness" of silence.
The apophatic factor of theology discloses not only an unknown or even unknowable feature of the Divine Mystery, but makes us aware that there remains a factor that cannot be put into words.A geometry of a triangle, a physics of a stone, or an astrophysics of the material universe will make it plain to us that we cannot know everything about those "objects". A theological reflection, on the other hand, will make us aware that those very "objects" have, as it were, an ingredient of silence, that their "essence" (all words fail) is untranslateable into concepts, ideas, and words. The unknown things in our scientific knowledge are on the same ontological level as the known facts; these unknown things have to be scientific truths. They are enigmas belonging to the epistemic order; they are un-known. On the other hand, the "referents" of apophatic theology are not modifications of kataphatic statements; these referents transcend the ontological order. They are mysteries -- the logos stands at the threshold. IN spite of its name, theology transcends the logos dimension of everything. The ineffable is different from the unknown.
We should not be overly clever about apophatism and dismiss it saying that "of what one can say nothing, one must keep silent." First of all, perhaps that which eludes our language may be the most important thing to try to spell out, lest we fall into utter passivity in the face of reality's resistance to being incarnated in language. Moreover, language is much more than conceptual language. Language is also symbolic, which amounts to more, not less, than metaphorical and practical language. The symbolon catapults us not only to the other shore (metaphora) and from there back to ourselves, but throws us to the mysterious core of that which the symbol symbolizes. Here we are already in the antechamber of apophatic theology. The Cloud of Unknowing, docta ignorantia, and the like are all linguistic tools of apophatic theology.
Finally and mainly, apophatic theology is not limited to saying nothing, but tries to unveil the vacuity that accompanies all linguistic statements. It does not tell us that the Mystery cannot be told -- that much we know from the very outset. It tells us that the logos is not everything, but that we cannot dispense with it. It tells us further that language is not everything, but awareness of the void, which is beyond, behind, beneath, and/or above all that language can say, requires us to undergo an abolishing or cleansing of ourselves. Emptiness is not Nothingness. Emptiness, like an infinitesimal calculus in an opposite direction, is that which "remains" once we have emptied ourselves from all our thoughts, representations, the mind itself, our very egos. The indic theology is emphatic about this...One does not know Brahman directly; Brahman is not an object of knowledge. One knows Brahman in every act of cognition, when it is a flash of awakening or illumination. Authentic knowledge is not an epistemological activity but an ontological state. The Divine Mystery is a question not of knowledge but of Being.
The mystical character of theology...stresses another important aspect of theology, that of experience. This experience in no way excludes critical awareness and the discernment of the intellect. Theology is not merely rational, but it is by no means irrational. This is a very traditional thesis of most theologies: theology belongs to the domain of faith. It is the product of an anubhava, an insight into the nature of reality. The language about the divine can only be a mystical language. Some would prefer to say a poetic language, and still others will, less poetically, speak of a religious language. In any case, it has to be a language of its own kind, for the referent is elusive, silent, transcendent, hidden, and immanent...
Since this is the case, it cannot be a language of mere information. We cannot use language as an instrument to link a subject (Man) to an object (God). Such a bridge would either destroy God or destroy itself before reaching the other shore. The practice of poets and lovers may help us understand this. You have to use a courteous language in which you dance aorund, suggest, run away, play hide and seek, make advances and retreats, say things you do not intend, do not mean, and do not understand...All you can do is to use a metaphor to make a retraction and add that you really did not mean to say that, since you do not want to say "it." You man "another thing," which is neither other nor a thing. Finally you fall into silence. And when they say that you do not know what you are talking about, you being to feel that they have finally understood what you wanted to say..."
(Rhythm of Being, pp. 203-204)
Now, I would imagine that one response to the above would be just the same as 9/10ths Penguin made to Windwalker's response previously:
9/10ths Penguin said:
If "God" describes the indescribable, then we're done. There is not - cannot be - any merit in any theistic position that's based on such a god.
Do you think that trading traditional god-concepts for this word-salad navel-gazing makes your position any better? Do you really think that atheists - or rational people generally - don't reject the literal nonsense that you're peddling?
But getting back to the question of the OP, I think this helps clarify the nature of the disagreement between the kind of "mystical" understanding of the Divine and a rationalistic atheism. The OP asks essentially whether theists and atheists actually agree but don't realize it. The answer to that is no, there is a real and meaningful difference between almost all "theism" and "atheism". But the fundamental disagreement doesn't always reduce to a disagreement about the existence of a particular entity, and so in that sense some theists agree with atheists that such an entity doesn't exist. But in reality the kind of theism discussed in the book I quoted does not evaluate the question of the Divine from the same philosophical presuppositions as the atheist position described by 9/10ths Penguin. His presuppositions are clear from the quote: What is important is to be strictly rational, and mystical language, by virtue of not being a purely rational language, is nonsense, even if it is careful to avoid inherent contradiction or sheer irrationality. But it is not a question of evaluating the hypothetical existence of a given entity using a mutually agreed upon epistemology. It is a more existential disagreement about the value of human experience and the priority of rationality. It is for this reason that I say that the analogy to God as a "flying pig" is insufficient.