Necessary Veils of God

"Wherefore God does not manifest Himself in anything but in His works and in His Word; because these can in some measure be comprehended, all other things which properly belong to his divinity, cannot be comprehended or understood, as they really are; such as those things which were beyond time and before the world's creation, etc. 

Perhaps God appeared to Adam unveiled; but after his sin He may have shown Himself to him in "a noise," (And they heard the voice of the LORD God walking in the garden in the cool of the day: Gen. 3:8), under which He was covered as with a veil. 

So also later in the tabernacle God was veiled by the sanctuary; and in the desert by the pillar of a cloud and by the pillar of fire. Wherefore Moses also calls these things "appearances" or "shadowings" of God, by which he then manifested Himself. 

---For our nature is so deformed by sin, yea corrupted and lost, that it cannot understand God unveiled nor comprehend what He really is. Therefore it is that these covering veils are absolutely necessary."

Martin Luther