There was very little that the mind of St. Augustine did not touch upon during his career as bishop of Hippo. Indeed Augustine had an intimate knowledge not only of the actions and results of sin, but of the motivations that were behind a sin. His approach of always being more patient and forgiving toward the sinner is all that much more remarkable.
Fr. John Vidmar shares with us some of St. Augustine’s thoughts on sin:
“No one, perhaps, understood the psychology of sin better than St. Augustine. He knew intimately the forces that played on people and the need to have compassion on the sinner. Hence, he instinctively hesitated to condemn those who did not measure up. He wrote: “Many sins are committed through pride, but not all happen proudly . . . They happen so often by ignorance, by human weakness; many are committed by men weeping and groaning in their distress.”
This sympathy for the sinner presented the church with a legacy of Christian forgiveness and a greater awareness of its mission in distinguishing hatred for sin from love for the sinner. Had St. Augustine done nothing else, this alone would have earned him the gratitude of future generations.”
 Father John Vidmar, OP. The Catholic Church Through the Ages. History. P. 72