As other postings indicate, the central theme clearly concerns redemption. The poem is incredibly tightly woven with recurring motifs that drive forward that message from multiple angles. Each insight per each canto is necessary to fully appreciate the lesson that follows. The plot itself is literally a story of Dante the Pilgrim's journey to Paradise, so on the most basic of level, the poem is a story of redemption. The allegory uses that driving plot line to illuminate the analogous spiritual journey from blindness, temptation, and weakness to enlightenment, free from distorted appetite.

Further, Dante the poet casts himself as a Pilgrim and puts himself on this journey. The opening canto suggests that Dante is having a midlife crisis in which he is lost "in dark woods" and psychologically and spiritually lost. In Robert Pinksy's translation, the poem begins with an overt claim of such: "Midway on our life's journey, I found myself / In dark woods, the right way lost." The work of the poem, for both Dante and the reader, is to find oneself or to "unlose" oneself in an act of intellectual and spiritual redemption.

The gradual turning from sin in the Inferno through the cleansing actions of Purgatoria to enlightenment in Paradisio is the work of redemption both the poet and the reader must accomplish in "our life's journey."

Dante's Divine Comedy relates to the theme of redemption in that Dante's character in the trilogy of poems is seeking to redeem himself after falling into a life of sin. The poem is an allegory because Dante's actions in the three sections of The Divine Comedy—Inferno, Purgatorio, Paradiso—represent a journey Dante makes from sinner, who has fallen off of "the path" to heaven and salvation, to redeemed Christian. He travels through these three possible "after-lives" and witnesses what happens to souls sent to each of these places. 

The Inferno is like a warning to Dante: if he does not straighten up, he will end up in one of these circles of hell being tortured for eternity. Purgatory is a place where souls can be purified and eventually earn their way into heaven, while Paradise is for those who have lived by God's principles and believe in Jesus Christ (Dante did not believe that those who did not accept Christ or even those who lived before Christ could achieve salvation).

Dante also chooses to set the three parts of his Divine Comedy on the symbolically significant Easter weekend: Good Friday, Holy Saturday, and Easter Sunday. Dante travels to hell on Good Friday, the day Jesus was crucified. On Saturday, he goes to Purgatory; the Saturday between the crucifixion and resurrection is an important waiting time, similar to what souls experience in Purgatory. Dante is guided to heaven by Beatrice on Easter Sunday, the day of Christ's resurrection. This three-day cycle in the Christian churches represents Jesus's salvation of mankind, as he earns eternal life for believers through his suffering and death. Jesus's sacrifice offers the opportunity for redemption to sinners like Dante who can recognize Christ as their savior and live as he did.