The main theme of Dante's epic is the quest for salvation, which encompasses all other themes within it. The Divine Comedy is essentially the tale of Dante’s enlightenment and, by extension, the reader’s. As Dante journeys through hell in Inferno, the reader gains insight into the widespread presence of sin. The endless sufferings of sinners, who exist without hope of redemption or relief, starkly illustrate the consequences of sin. As Dante and the reader move through the underworld, the spirits they encounter serve as concrete examples and offer instructive lessons on the seven deadly sins. By the end of Inferno, both Dante and the reader are better prepared to recognize and avoid sin in its various manifestations. Understanding sin is crucial for salvation and further spiritual development.

In the second part, Purgatory, Dante and the reader climb the Mountain of Purgatory toward the Garden of Eden at its peak. Along their ascent, they learn the importance of contrition and repentance, grasping the necessity of enduring suffering for the suffering they caused and for defying God. These lessons are reinforced through encounters with spirits who represent the seven deadly sins but now embody the longing for repentance and remorse.

The educational journey reaches its peak in the third section, Paradise, where numerous saved souls appear to Dante and explain the workings of grace and God’s love. In this celestial realm, Dante undergoes a series of what could be considered oral exams, testing his accumulated knowledge. Having been educated through his experiences in the three realms and gaining a thorough understanding of sin and grace, Dante passes his exams and attains the vision of God. He then assumes the role of a teacher himself, returning to earth with the purpose of writing about his experiences to benefit others.