Can it be known if God exists?
If there is no true knowing there can be no hierarchy of values. Nothing could be recognized as any more valuable (or correct) than anything else. All reality would be lateral, horizontal. Some questions need definitive answers. Will the building stand if it is built with these materials on this foundation? Does reality exist? While we can pose any possibility, we crave things to form some logical, consistent structure or pattern.
It is just as hard, if not more so, to prove God does not exist. As a matter of fact the same faculties (reality response) would have to be used to prove God’s existence or nonexistence.
Definition: the mind’s ability (associated with the brain but not the brain alone) to know the difference between 1) fact and fiction, 2) right and wrong, 3) good, better, best.
The ability to choose between relative or even absolute truth and error (science) or good and evil (moral) values represents the power of the human will.