Coming to a mutual agreement and some rambling.

[FemmeRealism]

It's logically possible belief one has knowledge of God to be a delusion.
It's logically possible belief one has knowledge of God to be knowledge.

Both are possible. The proof is simple, all these are logical possibilities (perhaps not actual possibilities in real world, just logical possibilities).

1) God not exists, so all belief in knowledge of him would be a delusion.
2) God existing, but not giving knowledge of himself, knowledge of himself is a delusion again.
3) God existing, and giving knowledge of himself, then belief in knowledge of him can be justified and rational.

No one has proven which one of these are true in a conclusive decisive manner to others.

I don't quiet think that the knowlage of God could be logial perse, since there is no solid, palpable evidence that God truly did create the Universe as we know it. However, I will say that the knowlage of God's excistance could be a delusion to those who follow it as fact, as they need a "hole filler" in their knowlage, say, on a scientific or spiritual level. It may be possible that a god, gods or "God" may truly excist, and we are thoroughly ignorant of this fact as said "God" or gods may excist with no acknowledgment of His, Her or Their presence.
While it is to that atheists (like myself) cannot completely disprove the existence of a higher divine deity, neither can any prove that such a deity does, truly, exist. While atheist cannot condemn the definite presence of a divine force such as a God, we request solid proof of His/Her presence, and have yet to be met by said evidence. However, neither can we disprove God's existance. And so births the religion impasse.