In A Christmas Carol, compassion is the main ingredient in the kindness and generosity cake that Dickens seems to crave. Scrooge gets a load of the contrast between those people who are willing to feel pity towards him (his ex-fiancée, his nephew, his clerk) and those who coldly dismiss him as he does them (fellow business people, his servants, the pawn shop owner). Then he reaches deep inside himself and finds a whole bunch of empathy that's he's been repressing, and—alakazam—he's flooded with nothing but good vibes toward those around him. After that, he transforms into a dude who can put himself into the shoes of others, and even forgive them for their misdeeds. In other words, he's now one of the people who are emotionally best equipped to live life.
Bonus! The person Scrooge learns to feel the most compassion for during his ghostly adventures is himself.
The only way to make the novella work is to have a totally unrealistic representation of how willing to forgive everyone is for a lifetime of Scrooge's misdeeds. Can you tell Shmoop can hold a grudge?