Scholars and critics have long recognized C. S. Lewis’s potent persuasiveness and acute audience awareness; however, only a few have written about Lewis’s self-designation as a “rhetor,” and scholarship exploring how Lewis’s writings work rhetorically remains in short supply. This article advances existing conversations about Lewis’s rhetoric through an investigation of appeals to ethos in his nonfiction. I contend that a primary way that Lewis establishes ethos is by demonstrating what Aristotle refers to as eunoia, goodwill towards one’s audience. Resonating with postures that Christians are often called to embrace during the Advent season, Lewis’s rhetoric of goodwill enables him to achieve one of his chief aims as a writer: preparing a way for the coming of the Lord into people’s lives. This mode of rhetorical engagement is also consistent with Lewis’s emphasis on the doctrine of the Incarnation, his interest in the concept of joy, and his conversion experience.