When Ebenezer Scrooge is visited by the Ghost of Christmas Present he is shown just how ill the boy really is (the family cannot afford to properly treat him on the salary Scrooge pays Cratchit). When visited by the Ghost of Christmas Yet to Come, Scrooge sees that Tiny Tim has died. This, and several other visions, lead Scrooge to reform his ways. At the end of the story, Dickens makes it explicit that Tiny Tim doesn't die, and Scrooge becomes a "second father" to him.
In the story, Tiny Tim is known for the statement, "God bless Us, Every One!" which he offers as a blessing at Christmas dinner. Dickens repeats the phrase at the end of the story; this is symbolic of Scrooge's change of heart.
Dickens often used his characters to demonstrate the disparity between social classes that existed in England during the Victorian era, and the hardships suffered at that time by the poor. These representative characters are typically children, presumably because children are most dependent upon others for survival, especially when they come from the lower social classes. Tiny Tim is among these characters, and is the most notable example in A Christmas Carol.
When the audience first meet Tiny Tim, he rests upon his father's shoulder, suggesting that while the Cratchits love their boy dearly, his situation is nonetheless a burden on the family. Further representative of this burden is Tiny Tim's crippled condition. That he is crippled evokes the financial issues that many poor families faced in 19th-century England. Although his spirit is robust, Tiny Tim's life expectancy is questionable. His crutch and iron frame support his frail body - 'bore a little crutch, and had his limbs supported by an iron frame', but more support is needed for Tim if he is to survive, as pointed out by the Ghost of Christmas Present in stave III: "I see a vacant seat in the poor chimney corner, and a crutch without an owner, carefully preserved. If these shadows remain unaltered by the future, the child will die." These are a microcosm of the impoverished population: without support or charity, their family will be reduced.
The relationship between Scrooge and Tiny Tim is a condensed depiction of the relationship between two social classes: the wealthy and the impoverished. Tiny Tim plays a large part in Scrooge's change. Tiny Tim's fate is linked very closely to Scrooge's fate, which tightens the connection that Dickens establishes between the two social classes. If Scrooge does not change his miserly ways, Tiny Tim is sure to die. Likewise, if the wealthy do not do their part to support the impoverished, the impoverished are sure to struggle. That Dickens framed this relationship with Christmas seems to suggest the immense need for decreasing the distance between English social strata. The proximity of the Christmas spirit to the issue of social strata lends a sense of community to Dickens’ message, urging the well-to-do upper class to consider the dependent poor, especially during the holiday, but year-round as well.