This a spin on A Christmas Carol, except this character eventually desires to earn the grandest mansion in heaven by giving on earth without earthly reward. I disagreed with it, at first, because I felt that we shouldn't serve only to earn a big heavenly mansion. Duh, it's symbolic, I realized. Using the idea of "good, better, best", trying to earn our place in heaven ranks only as "better", in my book.

So, if someone doesn't understand that the book is symbolic, they might serve to try and earn a literal mansion= "good".
If they see the mansion as symbolic, they might serve to earn their place/estate in heaven= "better".
It seems to me the best reason to serve is out of love. Simply because it's the right things to do, not because we'll get something for it. I've always appreciated the Hindu take on that. That is the reason Christ served. He served out of love while healing people and washing their feet. That is the best way. Of course, as the book explains, "good" is better than nothing at all. :) I have many days when I give nothing at all, and so this book is inspiring on many levels, just like A Christmas Carol is in its way.