Gregory the Great

It is said through the voice of the prophet to the soul that grows proud, "You trusted in your beauty and played the harlot because of your renown." For a soul to trust in its beauty is to presume within itself on its righteous works. It plays the harlot on the basis of its renown when in its righteous acts it seeks the glory of its own reputation rather than the spread of its Creator's praise.… What then is to be done in this case but that, when the malignant spirit of pride enjoys the good things that we have done in order to exalt the mind, we should ever recall to memory our evil deeds. The goal is that we may acknowledge our sinful acts as our own and our avoidance of sin as the gift of Almighty God. And so Paul says, "For this is the will of God, even your sanctification, that you abstain from unchastity."