The accusation of arrogance was your Argumentum ad hominem,
Interpretations and specifics will always vary because personal experience varies,
"Exists within Existence" is circular,
and you've ignored Custom's main point in favor of a Straw Man.
I don't think this is a serious conversation, anymore.
The god people describe is really generally only apart of themselves to begin with thus the argument is against the "believer". The fact people describe to the same religions and yet have vastly different beliefs to those of the same religion/god/deity/etc I believe is evidence enough of this fact.
I've dealt with people before that claim that god exists outside of existence which yeah... just...
Anyways matter and existence aren't the same thing matter is simply a form of energy where energy can exist in multiple different states. Must of what you are saying (to me atleast) appears to be going on about if matter were existence which isn't the case, matter is within existence but it isn't existence itself.
@R3sistance said "... to understand something, it must first actually exist within existence ..."
That is an interesting statement. If by "within existence" you mean "within the known material universe", then do you intentionally conclude that mathematicians do not understand their subject? Or are you in the camp that all mathematics, no matter how seemingly abstract, describes some aspect of our material universe, because otherwise we would not be able to comprehend it? (Philosophers have wondered why the requisite math seems to precede the physics.)
In my observation, the conscious awareness of something requires a symbol - usually verbal. Having the sensory equipment to detect some aspect of your environment is not enough to make you consciously aware of that aspect. For instance, while the physical color receptors have been around for much longer, the conscious awareness of color has evolved in just a few thousand years. See http://www.radiolab.org/story/211213-sky-isnt-blue/ for a fun overview. The color data still benefited humans before color awareness through the subconscious mind.
In "Saving the Appearances", Owen Barfield argues that phenomenon (what we perceive) are a subjective response of the human organism to an unknown underlying base of reality, and that response evolves throughout human history, with a corresponding evolution in what is perceived. He calls this the "evolution of consciousness". https://en.wikipedia.org/wiki/Saving_the_Appearances:_A_Study_in_Idolatry