Cur Deus Verba unfolds a systematic theology of Scripture from a single key question: What did God seek to accomplish by making the Bible? The answer requires seeing why the Holy Trinity made anything at all, why the Word became flesh, and finally why the Church needs an inspired text. As Christ is more fully "man" than any mere man, so his Church is more fully "society" than any merely human society. And as every society has its literary tradition, so the Church needed a canon of literature that would be more fully "book" than any merely human book.
But to grasp what God intended to accomplish, we have to see how he intended to do it. To the extent possible, God wanted human beings to cause not just the text but revelation itself, and paradoxically this exaltation of human agency gave rise to the need for Scripture’s spiritual sense. The spiritual sense of Scripture leads in turn to a meaning of the term "literal" that is unique to the realm of theology, and the connection between the two means that we cannot follow the literal sense without grasping the spiritual as well.
Once God has made what he intended in the way he intended, one question remains: How does this inspired text continue to exist? As with any text, the answer is that Scripture exists in physical books, but really and principally in the hearts of the readers. And Scripture's own place in the salvation history it records means that one human heart is preeminent: the text of Sacred Scripture exists exemplarily in the Heart of Jesus Christ.