Courtesy of the Pontifical Institute of Christian Archaeology

Young women gather stones to build a tower, center, in this third-century painting from the Catacomb of San Gennaro, in Naples. The recently restored painting is the only known ancient representation derived from The Shepherd of Hermas, a long, revelatory text composed in early second-century Rome. The document tells the story of Hermas, a freed slave who has visions of heaven and who learns from his spiritual guide, the shepherd, the importance of a fundamental change of heart—from hesitation and double-mindedness to simple faith.

The ceiling painting depicts a tower first mentioned in one of Hermas’s five visions and revisited in a parable told to Hermas by the shepherd. The stones carried by the maidens in the catacomb painting represent various peoples and their different responses to the call of faith. Square white stones, perfect for the tower, represent faithful church leaders and martyrs, while stones that require trimming represent people who must sever their associations with wealth and power. Stones cast aside nearby signify people who must have a change of heart before acceptance by the church.

Although highly popular with early Christians—and considered canonical by several church fathers—the vivid revelatory account of The Shepherd of Hermas did not make it into the New Testament, and the document is little known today.