Karlstadt's commentary on Augustine's "De spiritu et littera" is an exceptional resource for understanding Karlstadt's conversion and his continued development into a reformer in these years of rapid change in Wittenberg (1517-1519). Alyssa Lehr Evans shows his "learning by doing," how he self-consciously transitioned away from his scholastic career and developed new ways to move forward, even while still holding on for a time to traditional methods and style. Karlstadt openly wrestled with fundamental questions about which religious sources are authoritative and how they ought to be read. Evans shows how Karlstadt's reading and reception of Augustine played a pivotal role in his development and affected his theology and its practical applications, even his writing style. Placing this commentary and surrounding writings in their historical context provides a deeper understanding of Karlstadt's early thought, his reading and working methods, as well as his active role in the emergence of the reformation in Wittenberg. This work was awarded the 2025 Manfred Lautenschlaeger Award for Theological Promise.