Take a story's temperature by studying its tone. Is it hopeful? Cynical? Snarky? Playful?
Humble, Repentant, and God-Glorifyin'
There is no shortage of "Lord I have sinned, please forgive my sinning soul because I am a sinner and I don't deserve your mercy"-type language in the Confessions. Think groveling, big time. Like:
But, dust and ashes though I am, let me appeal to your pity, since it is to you in your mercy that I speak. (I.6.1)
What crooked paths I trod! (VI.16.3)
What evil have I not done […] But you, O Lord, are good. You are merciful. (IX.1.2)
The running theme here is that Augustine has done wrong, and is unworthy of God's mercy, but God is going to give it to him anyway because God is good like that.
One of the things Augustine is trying to do with this tone is rid himself of all Pride (see our Themes section). Confession, or owning up to all the bad things you've done, is a good first step toward humility, but Augustine likes to lay the wretchedness on thick. After all, God doesn't just dole out the mercy like it's Halloween candy; Augustine wants to show us that it takes a lot of genuine contrition before we can make our sinning selves worthy.
Glorifying
You won't find any, "Well, God is all right, I guess… He's pretty good as far as gods go" language in the Confessions. Augustine is a prime example of what it means to devote every second of your life to God. Hey, when you've been as bad as Augustine has been (in his mind, at least), that's what it takes. Augustine's just setting an example for the rest of us sinners.
When you read the Confessions it almost feels like he has a God-praising quota. There aren't many sentences that don't contain some sort of phrase like "Blessed are those who love you, O God" (IV.9.1). Augustine sees God in everything and has a lot of different names for him too. You'll see him saying "O Lord my God, my Light, my Wealth, and my Salvation" (IX.1.3) and "Eternal Truth, true Love, beloved Eternity—all this, my God you are, and it is to you that I sigh by night and day" (VII.10.2). He's basically doing in writing what he believes people should be thinking. Every moment, of every hour, of every day of their lives.