A long and personal text about the role Christianity played in the life of a man in fifth century. We are lucky to have it. I don't know of any older text that are this personal and of any substantial length. It's well worth reading just to look into the mind of somebody who lived almost 2000 years ago. You do not get this with Plato or anywhere in the bible.
Some examples of the style:
"And how shall I call upon my God, my God and Lord, since, when I call for Him, I shall be calling Him to myself? and what room is there within me, whither my God can come into me? whither can God come into me, God who made heaven and earth? is there, indeed, O Lord my God, aught in me that can contain Thee? (...) Narrow is the mansion of my soul; enlarge Thou it, that Thou mayest enter in."
"Passing hence from infancy, I came to boyhood, or rather it came to me, displacing infancy. Nor did that depart,—(for whither went it?)—and yet it was no more. For I was no longer a speechless infant, but a speaking boy. This I remember; and have since observed how I learned to speak. It was not that my elders taught me words (as, soon after, other learning) in any set method; but I, longing by cries and broken accents and various motions of my limbs to express my thoughts, that so I might have my will, and yet unable to express all I willed, or to whom I willed, did myself, by the understanding which Thou, my God, gavest me, practise the sounds in my memory."
How many ancient texts are this personal? This could be a stream of consciousness in a novel. Text by Seneca, Cicero and the like are more like essays.
Seems like you learned Greek by reading Homer, not the bible. "Why then did I hate the Greek classics, which have the like tales? For Homer also curiously wove the like fictions, and is most sweetly vain, yet was he bitter to my boyish taste. And so I suppose would Virgil be to Grecian children, when forced to learn him as I was Homer. Difficulty, in truth, the difficulty of a foreign tongue, dashed, as it were, with gall all the sweetness of Grecian fable." Not at all a priori obvious it would be so.
Him about his youthful sins
"For I even burnt in my youth heretofore, to be satiated in things below; and I dared to grow wild again, with these various and shadowy loves: my beauty consumed away, and I stank in Thine eyes; pleasing myself, and desirous to please in the eyes of men. And what was it that I delighted in, but to love, and be loved? but I kept not the measure of love, of mind to mind, friendship's bright boundary: but out of the muddy concupiscence of the flesh, and the bubblings of youth, mists fumed up which beclouded and overcast my heart, that I could not discern the clear brightness of love from the fog of lustfulness. Both did confusedly boil in me, and hurried my unstayed youth over the precipice of unholy desires, and sunk me in a gulf of flagitiousnesses."
"Theft is punished by Thy law, O Lord, and the law written in the hearts of men, which iniquity itself effaces not. For what thief will abide a thief? not even a rich thief, one stealing through want. Yet I lusted to thieve, and did it, compelled by no hunger, nor poverty, but through a cloyedness of well-doing, and a pamperedness of iniquity. For I stole that, of which I had enough, and much better. Nor cared I to enjoy what I stole, but joyed in the theft and sin itself. A pear tree there was near our vineyard, laden with fruit, tempting neither for colour nor taste. To shake and rob this, some lewd young fellows of us went, late one night (having according to our pestilent custom prolonged our sports in the streets till then), and took huge loads, not for our eating, but to fling to the very hogs, having only tasted them. And this, but to do what we liked only, because it was misliked. Behold my heart, O God, behold my heart, which Thou hadst pity upon in the bottom of the bottomless pit. Now, behold, let my heart tell Thee what it sought there, that I should be gratuitously evil, having no temptation to ill, but the ill itself. It was foul, and I loved it; I loved to perish, I loved mine own fault, not that for which I was faulty, but my fault itself. Foul soul, falling from Thy firmament to utter destruction; not seeking aught through the shame, but the shame itself!"
The dangerous thing about Augustine
"Curiosity makes semblance of a desire of knowledge; whereas Thou supremely knowest all. Yea, ignorance and foolishness itself is cloaked under the name of simplicity and uninjuriousness; because nothing is found more single than Thee: and what less injurious, since they are his own works which injure the sinner? Yea, sloth would fain be at rest; but what stable rest besides the Lord? Luxury affects to be called plenty and abundance; but Thou art the fulness and never-failing plenteousness of incorruptible pleasures. Prodigality presents a shadow of liberality: but Thou art the most overflowing Giver of all good. Covetousness would possess many things; and Thou possessest all things. Envy disputes for excellency: what more excellent than Thou? "
It is not life affirming, not about growth. It's the faith of a tired old man.