"Do you suppose, daughters, that He is alone when He comes to us? Do you not see that His most holy Son says: "Who art in the Heavens"? Surely such a… - Teresa of Ávila

Untilled ground, however rich, will bring forth thistles and thorns; so also the mind of man.

I used unexpectedly to experience a consciousness of the presence of God, or such a kind that I could not possibly doubt that He was within me or that I was wholly engulfed in Him. This was in no sense a vision: I believe it is called mystical theology. The soul is suspended in such a way that it seems to be completely outside itself. The will loves; the memory, I think, is almost lost; while the understanding, I believe, thought it is not lost, does not reason — I mean that it does not work, but is amazed at the extent of all it can understand; for God wills it to realize that it understands nothing of what His Majesty represents to it.

by committing a mortal sin, instead of seeking to please God, it prefers to gratify the devil, the prince of darkness, and so comes to share his blackness.