The following (extremely applicable article) was written back in 1161, by Matthew Mead. It is taken from "The Almost Christian":

“There is a proud heart in every natural man. There was much pride in Adam's sin—and there is much of it in all Adam's sons. Pride is a radical sin, and from hence arises this over-inflated opinion of a man's spiritual state and condition: ‘The Pharisee stood up and prayed about himself: God, I thank you that I am not like other men— robbers, evildoers, adulterers’ (Luke 18:11). This is the unsaved man's motto.

A proud man has an eye to see his beauty—but not his deformity. He sees his abilities—but not his spots. He sees his seeming righteousness—but not his real wretchedness. It must be a work of grace—which must show a man the lack of grace. The haughty eye looks upward—but the humble eye looks downward, and therefore this is the believer's motto, ‘I am the least of saints—and the greatest of sinners!’

"‘But the tax collector stood at a distance and dared not even lift his eyes to heaven as he prayed. Instead, he beat his chest in sorrow, saying, 'O God, be merciful to me, for I am a sinner!' I tell you, this sinner, not the Pharisee, returned home justified before God!’ (Luke 18:13-14).