Quote from the book "Галаад"

It was to the effect that you can assert the existence of something;—Being — having not the slightest notion of what it is. Then God is at a greater remove altogether if God is the Author of Existence, what can it mean to say God exists? There’s a problem in vocabulary. He would have to have had a character before existence which the poverty of our understanding can only call existence. That is clearly a source of confusion. Another term would be needed to describe a state or quality of which we can have no experience whatever, to which existence as we know it can bear only the slightest likeness or affinity. So creating proofs from experience of any sort is like building a ladder to the moon. It seems that it should be possible, until you stop to consider the nature of the problem.