Central to Augustine's philosophical project throughout his career is the question of how we can acquire knowledge of God. In his early dialogues, Augustine argues that knowledge of the liberal arts is a necessary condition for knowledge of the divine nature. But it is unclear what the liberal arts---dialectic, grammar, rhetoric, arithmetic, geometry, astronomy, and music---have to do with divinity. I show that to answer this question we must examine both the subject matter and the structure of the liberal arts. In his early dialogues, Augustine suggests that the subject matter of the liberal arts is the eternal and immutable intelligible Forms, i.e., the non-perceptual, abstract, archetypal objects which structure and undergird reality. Each liberal art corresponds to a segment of intelligible reality (e.g., arithmetic to numbers and dialectic to valid modes of inference). These intelligibles, as contents of the divine mind, make the liberal arts necessary for coming to grasp God's nature in that they offer glimpses of the eternal divine essence. Regarding their structure, Augustine holds that each liberal art is composed of definitions and theorems. Unlike contemporary philosophers who regard definitions as conventional, Augustine maintains that definitions pick out essential properties of the intelligibles. Furthermore, my analysis shows that the liberal arts are structured as axiomatic-deductive sciences: definitions capture first principles or fundamental truths and the axiomatic structure reflects how theorems are grounded in these definitions. This structure provides explanatory understanding of distinct segments of intelligible reality. In this way, by learning the liberal arts, we acquire understanding of the very structure of intelligible reality and are better positioned to grasp the divine essence. I also suggest that in his later works, Augustine recognizes that certain key tenets of Christianity---e.g., God's triune nature, Christ's resurrection, and the incarnation---cannot be grasped merely through learning the liberal arts. He acknowledges that accepting the authoritative reports of scripture will be necessary for coming to know and understand these fundamental Christian beliefs.