This essay examines the influence of apocalyptic literature and the significance of apocalyptic themes in the Catholic Epistles. While none of the Catholic Epistles is an apocalypse by genre, they all manifest various apocalyptic themes. James reflects a synthesis of apocalyptic and wisdom traditions. The letter of 1 Peter is saturated with apocalyptic themes. This essay therefore selectively investigates the apocalyptic influence in three specific passages: 1 Pet 1:10–12, 3:18–22, and 4:1–6. Jude and 2 Peter, treated together, are deeply saturated in the world of Jewish apocalyptic literature, with Jude directly quoting from 1 Enoch. The essay briefly examines these connections, with particular attention to epistemology, otherworldly places and beings, and eschatology. Apocalyptic themes in the Johannine Epistles are investigated, with particular attention to how the themes of epistemology, cosmology, and eschatology are transmitted through the dualism of the letters.