Many people think that they are achieving great things in external works such as fasting, going barefoot and other such practices which are called penances. But true penance, and the best kind of penance, is that whereby we can improve ourselves greatly and in the highest measure, and this consists in turning entirely away from all that is not God, or of God in ourselves and in all creatures, and in turning fully and completely towards our beloved God in an unshakable love so that our devotions and desire for him become great. God is in himself so exalted that he is beyond the reach of either knowledge or desire. Desire extends further than anything that can be grasped by knowledge. It is wider than the whole of the heavens, than all angels, even though everything that lives on earth is contained in the spark of a single angel.
Desire is wide, immeasurably so.
But nothing that knowledge can grasp or desire can want, is God. Where knowledge and desire end, there is darkness, and there God shines.