The placement of powerful figures within a nocturnal landscape in Sebastiano del Piombo’s Viterbo Pietà (ca. 1512–16) is commonly explained as a stylistic union of Michelangelo’s Tuscan disegno and Sebastiano’s Venetian colorito. Yet this dialectic became a concern to art theorists only later in mid-century. As this essay shows, Sebastiano’s work can be situated within a more immediate context: the reform ideas of the Augustinian prior general Giles of Viterbo, particularly his revival of Augustine’s reflection on time and eternity. Like Giles’s Christian poetics, the painting considers how an image can convey the immutability of God to the viewer, who sees everything within time. Sebastiano’s work thus lays claim to a new kind of modern devotional image, or Andachtsbild, that interrogates the very mechanism of corporeal vision in bringing one closer to the divine, drawing on the metaphor of nature’s mutability advanced by Giles in the early years of Catholic reform.