Scrooge learns that the purpose of life is to take care of other people when one can. Marley tells him early on, "'Mankind was my business. The common welfare was my business [...]." In other words, he ought to have been spending his time engaged in the business of life rather than the business of profit. Marley also says that
It is required of every man [...] that the spirit within him should walk abroad among his fellowmen, and travel far and wide, and if that spirit goes not forth in life, it is condemned to do so after death. It is doomed to wander through the world [...] and witness what it cannot share, but might have shared on earth, and turned to happiness!
Thus, Marley makes it clear that what we are supposed to do in life is to travel around among other people and to share a fellowship with them, helping them as we can in whatever ways we can. This is the way to achieve happiness and to leave a lasting impact on the world (and to avoid the hellish afterlife that Scrooge...
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