In Literary Theory class, professor Potolsky introduced us to a concept called "Sortes Virgilianae" which he explained (as a model) was sort of common to conversion narratives, including that of St. Augustin. "Sortes Virgilianae" according to wikipedia, is a form of divination derived from randomly selected verses of Virgil's Aenaeid. The conversion narrative parallel would be with a reader (for instance, Augustin) who, randomly opens the Bible and finds "the perfect text" - a moment of pure inspiration.
As an honest person, I recognize this form of divination as common both in myself and in my culture. Although I don't use my religious (or secular) texts to predict the future on that metaphorical level - most religious texts contain clear prophecy - I have sought inspiration from unconsciously selected pages or verses.
I don't believe in divination of any kind, and I don't consider myself superstitious, and yet I continue to put my faith in some few religious text. Within reason (there are always a few precious moments involving decapitation, blood, guts, sex, and other fascinating, historical moments), almost any piece of scripture in or out of context can provide inspiration as either an act of obedience as a way of "knocking" as it says in Matthew 7:7 (among other places), or as a moment of meditation, aligning one's thoughts with God's. Perhaps this was the inspiration of which Augustin spoke.
I also believe in a third possibility; that God allowed/created a miracle. When one shows willingness to go to the scriptures, sometimes the instead of pure inspiration or the communication of the Holy Ghost, the scripture itself is the object of prophecy. This kind of miracle should not be expected with every attempt, but I maintain that this kind of material manifestation of divine grace can and does happen. This kind of miracle is likely also restricted to specific holy texts.