To have a solid footing and to avoid stumbling, consistently puncture the cloud of unknowing that is between you and God with a sharp dart of longing love. Avoid thinking of anything less than God, and do not quit your time of contemplation regardless of what may happen. Loving contemplation destroys our tendency to sin more effectively than any other practice. Contemplation is superior to your fasts and vigils, regardless of how early in the morning you get up, the hardness of your bed, or the roughness of your hair shirt. Even if it were lawful for you to blind yourself, cut your tongue from your mouth, plug up your ears and nose, cut off your limbs and become a eunuch, none of these physical tortures would be of any value to you. The impulse to sin would still be in you.
Moreover, regardless of how much you fret about your sins in your straying thoughts or think of the joys of heaven, what do you gain? All of the value you gain from such practices fades when compared with the impulse of love. This, without anything else, is what Jesus described Mary’s “best part.” When detached from loving desire, religious practices have little or no spiritual results.
The Cloud of Unknowing, Chapter 12