The beautiful thing about this book is that the spirits that haunt Scrooge don't teach him anything. All they do is show him scenes from his past/present/future, and by viewing his life from a higher perspective, Scrooge teaches himself. Thus comes his change of heart.
I love the way each spirit is described and the symbolism of it. The ghost of Christmas present as a banquet feast (living in the moment=feasting at the table of life), and the ghost of the future described as darkness and mystery (because it doesn't even exist, it's only what we perceive). It was enlightening for me to read this book after only ever having watched The Muppet Christmas Carol every year (which is actually a very close interpretation of the book--uses many of the same lines, etc.). I enjoyed this holiday read! It made me cry! Just like the Muppet Christmas Carol always does! :)