A Christmas Carol is a fairly straightforward allegory built on an episodic narrative structure in which each of the main passages has a fixed, obvious symbolic meaning. The book is divided into five sections (Dickens labels them Staves in reference to the musical notation staff--a Christmas carol, after all, is a song), with each of the middle three Staves revolving around a visitation by one of the three famous spirits. The three spirit-guides, along with each of their tales, carry out a thematic function--the Ghost of Christmas Past, with his glowing head, represents memory; the Ghost of Christmas Present represents charity, empathy, and the Christmas spirit; and the reaper-like Ghost of Christmas Yet to Come represents the fear of death. Scrooge, with his Bah! Humbug! attitude, embodies all that dampens Christmas spirit--greed, selfishness, indifference, and a lack of consideration for one's fellow man.
With A Christmas Carol, Dickens hopes to illustrate how self-serving, insensitive people can be converted into charitable, caring, and socially conscious members of society through the intercession of moralizing quasi-religious lessons. Warmth, generosity, and overall goodwill, overcome Scrooge's bitter apathy as he encounters and learns from his memory, the ability to empathize, and his fear of death. Memory serves to remind Scrooge of a time when he still felt emotionally connected to other people, before he closed himself off in an austere state of alienation. Empathy enables Scrooge to sympathize with and understand those less fortunate than himself, people like Tiny Tim and Bob Cratchit. The fear of death hints at imminent moral reckoning--the promise of punishment and reward.
With each Ghost's tale functioning as a parable, A Christmas Carol advances the Christian moral ideals associated with Christmas--generosity, kindness, and universal love for your community--and of Victorian England in general. The book also offers a distinctly modern view of Christmas, less concerned with solemn religious ceremony and defined by more joyous traditions--the sharing of gifts, festive celebrations, displays of prosperity. The book also contains a political edge, most evident in Dickens' development of the bustling, struggling Cratchit family, who are a compelling, if one-dimensional, representation of the plight of the poor. Dickens, with every intention of tugging on your heartstrings, paints the Cratchits as a destitute family that finds a way to express profound gratitude for its emotional riches. Dickens carries this sentiment even further with the tragic figure of the pure-hearted, crippled Cratchit son, Tiny Tim. Scrooge's emotive connection to Tiny Tim dramatically underscores his revelatory acceptance of the Christmas ideal. Scrooge begins to break through his emotional barricade in Stave Three as he expresses pity for Tiny Tim. The reader, upon hearing the usually uncaring miser inquire into Tim's fate, begins to believe Scrooge has a chance at salvation. Scrooge's path to redemption culminates with his figurative "adoption" of Tiny Tim, acting as "a second father" to the little boy.