In my reading of spiritual masters, I have noticed that persons we now view as saintly have a finely calibrated sense of sin. Aware of God's ideal, aspiring to holiness, free of the vanity and defensiveness that blind most people, they live in full awareness of falling short. Thomas Merton makes this point in an odd comparison between Adolf Hitler and Theresa of Avila:

Saint Theresa thinks everybody is the same as she is because we are all sinners. Hitler thinks everybody is different from him, because they are, some of them less pure, some of them less noble, some of them less intelligent, some of them less beautiful, all of them less godlike, all of them less perfect. It is the Hitlers who think they are perfect—because nobody else thinks so. It is the saints who know they are not perfect, although sometimes other people say of them that they are saints: the saints themselves know themselves only as sinners, liable to lose their love and the sight of Christ through a movement of impatience or selfishness or pride.

True saints do not get discouraged over their faults, for they recognize that a person who feels no guilt can never find healing. Paradoxically, neither can a person who wallows in guilt. The sense of guilt only serves its designed purpose if it presses us toward the God who promises forgiveness and restoration.

Philip Yancey, Guilt Good and Bad, The early warning signs.