On Humility:

The unholy demons once began to murmur praise in the heart of an ascetic who was struggling to achieve blessed humility. However, God inspired him to use a holy trick to defeat the cleverness of these spirits. The monk got up and on the wall of his cell he wrote in sequence the names of the major virtues: perfect love, angelic humility, pure prayer, unassailable chastity, and others of a similar kind. The result was that whenever vainglorious thoughts began to puff him up, he would say: "Come! Let us go to be judged." Going to the wall he would read the names there and would cry out to himself:" When you have every one of these virtues within you, then you will have an accurate sense of how far from God you still are."

St. John Climacus, The Ladder of Divine Ascent