(If you get bored reading this, just know I'm wrapping this all back to God.)
A thinking entity is placed in a realm by a higher power.
This thinking entity knows EVERYTHING about his realm. He has memories of creating it from nothing. He has the knowledge that he has always existed. He knows everything there is in the realm. He knows everything that will ever happen in the realm, and everything that ever was.
He must understand that him being a product of an entity unreachable by himself is a scenario.
If he doesn't understand this, than he is not omniscient and we've already won the argument.
Here comes the problem.
(Assuming omniscience does not entail omnipotence..)
Is it possible to know whether or not there exists things that you do not and can not know of?
Think back to the scenario. The thinker in the realm may know everything he is capable of knowing, never encounters something that he doesn't already know, and therefore concludes that he is omniscient... yet he must realize that it is still possible that there exists things he cannot reach or know of. He must realize that it is still possible that he is the product of an unreachable entity.
The only thing or thinker capable of concluding omniscience is the thinker itself. Otherwise, if it has to be told that it is omniscience, then it is not omniscient because that entails that there was something it did not know.. that it was omniscient.
So.. set aside all dictionary absolutes..
-A thinker exists.
-A thinker never encounters anything it does not know.
-The thinker concludes omniscience.
The thinker is not really omniscient unless it realizes that it is impossible to know of things that are impossible, for the thinker, to know.
-The thinker cannot be omniscience.
UNLESS
-The thinker is omnipotent.
How does the thinker know he or she is omnipotent?
-The thinker never encounters something he or she cannot do.
The thinker is not really omniscient unless it realizes that it is impossible to encounter things that cannot be done when they are impossible, for the thinker, to know.
In other words.. the thinker in the realm never encounters something it cannot do if it never knows of something it can't do.
-The thinker realizes this, and cannot conclude omniscience.
-The thinker does not realize this... and is not omniscience because it hasn't realized something.
Thus..
Omniscience is impossible.
Thus.. God is either not omniscient or a liar.
The point is, to be omniscient, the thinker must be aware that if there are things that are unknowable by itself, then it does not know of those things. Whether those things exist is irrelevant. It's the fact that the thinker is aware that it cannot know something: it cannot know if there exists things that are unreachable or unknowable by the thinker itself.
(or I messed up in my thought process somewhere.. that's where you come in
I literally started this thread with nothing planned out.. so there's bound to be a mess up somewhere)