The theme of "The Christmas Carol" is the power of redemption. The story follows the journey of a grumpy, stingy old man named Ebenezer Scrooge as he is visited by the ghosts of Christmas past, present, and future. Through the ghosts' visits, Scrooge is forced to confront his selfishness and lack of empathy, and he ultimately finds redemption in the end. The story teaches the importance of empathy and kindness, and that it is never too late to change for the better.