My beef with proving God's existence

I hate to come back to this again, but I, like Jen, cannot let it go. In class, we had quite the discussion about whether a belief in God implies the existence of God (or whether the first can exist without the second), and although I originally thought that the first could indeed exist without insisting on the second, I have a slightly altered view after a couple weeks of mulling it over. First, I want to distinguish between the idea of God and God himself, at least in terms of existence, to help make my claims clearer (hopefully). Keeping that distinction in mind, I claim that a belief in God not only infers the idea of God but demands it. This concept is somewhat trivial- in order to believe in God, one must have some pre-existing idea of what God is, i.e. what it is that defines God; whether it be that he is the ultimate power and knower or whether he is pure perfection, one must have some idea of what he is in order to believe in him. Scholars of Descartes would argue that this necessitates the existence of God, insofar as we have some concept of perfection in our minds, and while this is an argument for another day, I think in short that it is just as easy for us to have created the word perfection to describe what seems complete to us and for us to be completely mistaken than for us to have an accurate idea of what completeness truly is and for us to term it as such. Anyhow, my main problem with asserting that belief in God necessitates or infers the existence of God is that it seems to assume that we can prove the existence of God as if he is an object. Think about it this way- when we speak of existence, what do we mean? We mean that we have experienced a thing or something similar in a certain state that we term "existing". When I say "I exist," I mean that I continuously experience my own Being disclosed in a being by way of thinking, walking, looking in the mirror, getting bitten by a mosquito, etc. When I say "tigers exist," I mean that if I went to Africa, it would be simple for me to point at a Tiger and say "look, a tiger" or that I saw a tiger in a national geographic film. When I say "God exists," however, how can I supply evidence for my claim? Although Descartes' solution is a clever one, it seems just as simple for me to say that I received the idea of completeness from a drawing of a circle, which even the most simple minded child could produce, even on accident. I cannot say that I have or could readily experience God as I could any other object- he is not a site at which Being is disclosed, but rather he is Being (possibly). At any rate, while I can certainly postulate that God exists in order to make my own experiences more relevant and meaningful to me, I cannot declare God's existence absolutely and outside myself because it would be doing so as if he is an object, which he is most certainly not.

I understand that there are many holes in this, and I invite criticism/comments- I struggled for weeks with these ideas and this is the brief version of my conclusion, although I am still wavering on many fronts. I guess at the root of it all it just seems, to me, both immoral and against all intuition and reason to attempt to claim for all others' existence that God exists.