The spiritual function of fierce terrain (in the apophatic tradition) is to bring us to the end of ourselves, to the abandonment of language and the relinquishment of ego. A vast expanse of jagged stone, desert sand, and towering thunderheads has a way of challenging all the mental constructs in which we are tempted to take comfort and pride, thinking we have captured the divine. The things that ignore us save us in the end.
Abba Paul went to see Abba Basil and said, "Abba, as far as I can, I say my little office, I fast a little, I read and meditate, I live in peace and as far as I can, I purify my thoughts. What else can I do?"
Then the old man stood up and stretched his hands towards heaven. His fingers became like ten lamps of fire and he responded, "If you will, you can become all fire. You cannot be a monk unless you become like a consuming fire."