I once heard a spiritual man say that he was not so much astonished at the things done by a soul in mortal sin as at the things not done by it. May God, in His mercy, deliver us from such great evil, for there is nothing in the whole of our lives that so thoroughly deserves to be called evil as this, since it brings endless and eternal evils in its train. It is of this, daughters, that we should walk in fear, and this from which in our prayers we must beg God to deliver us; for, if He keep not the city, we shall labour in vain,31 since we are vanity itself. That person to whom I referred just now said that the favour which God had granted her had taught her too things: first, she had learned to have the greatest fear of offending Him, for which reason she continually begged Him not to allow her to fall, when she saw what legible consequences a fall could bring; secondly, she had found it a mirror of humility, for it had made her realize that any good thing we do has its source, not in ourselves but rather in that spring where this tree, which is the soul, is planted, and in that sun which sheds its radiance on our works. She says that she saw this so clearly that, whenever she did any good thing, or saw such a thing done, she betook herself straightway to its Source, realizing that without His help we are powerless. She then went on at once to praise God; and, as a rule, when she did any good action, she never gave a thought to herself at all.