Job is a broken and changed man. That’s what happens when you really see God. It happened to Isaiah: “Woe is me! For I am lost; for I am a man of unclean lips … for my eyes have seen the King, the Lord of hosts!” (Isaiah 6:5). It happened to Peter when Jesus showed his power: “Depart from me, for I am a sinful man, O Lord” (Luke 5:8). It happened to the centurion when Jesus came to his house: “Lord, do not trouble yourself, for I am not worthy to have you come under my roof” (Luke 7:6).

Before Job saw God in this way, he had esteemed himself somewhat highly and had not hesitated to assert his righteousness. Now he sees himself more clearly. And what he sees drives him to repentance.

If we don’t feel grieved for our sin, and deeply unworthy of God’s goodness, then we need to pray earnestly that God would show us Himself—that He would cease to be a mere doctrine that we hear with our ear, and instead would become an awesome, infinitely holy, dreadful, and wonderful Sovereign that we taste and see with our hearts.

John Piper, Reversal in Suffering

http://www.desiringgod.org/resource-library/sermons/job-reversal-in-suffering