Book X – Augustine treats the purpose and fruit of making these personal “confessions”:
Let me know Thee, O Lord, who knowest me: let me know Thee, as I am known. Power of my soul, enter into it, and fit it for Thee, that Thou mayest have and hold it without spot or wrinkle. This is my hope, therefore do I speak; and in this hope do I rejoice, when I rejoice healthfully. Other things of this life are the less to be sorrowed for, the more they are sorrowed for; and the more to be sorrowed for, the less men sorrow for them. For behold, Thou lovest the truth, and he that doth it, cometh to the light. This would I do in my heart before Thee in confession: and in my writing, before many witnesses.
…But do Thou, my inmost Physician, make plain unto me what fruit I may reap by doing it. For the confessions of my past sins, which Thou hast forgiven and covered, that Thou mightest bless me in Thee, changing my soul by Faith and Thy Sacrament, when read and heard, stir up the heart, that it sleep not in despair and say “I cannot,” but awake in the love of Thy mercy and the sweetness of Thy grace, whereby whoso is weak, is strong, when by it he became conscious of his own weakness. And the good delight to hear of the past evils of such as are now freed from them, not because they are evils, but because they have been and are not. With what fruit then, O Lord my God, to Whom my conscience daily confesseth, trusting more in the hope of Thy mercy than in her own innocency, with what fruit, I pray, do I by this book confess to men also in Thy presence what I now am, not what I have been? For that other fruit I have seen and spoken of. But what I now am, at the very time of making these confessions, divers desire to know, who have or have not known me, who have heard from me or of me; but their ear is not at my heart where I am, whatever I am. They wish then to hear me confess what I am within; whither neither their eye, nor ear, nor understanding can reach; they wish it, as ready to believe—but will they know? For charity, whereby they are good, telleth them that in my confessions I lie not; and she in them, believeth me.
St.Augustine, Confessions, found online here at Christian Classics Ethereal Library