Greed, for Lack of a Better Word, is Bad
Ebenezer Scrooge is basically a decent young man who is corrupted by sinister businessman Mr. Jorkin whose embezzlement eventually results in the infamous partnership of Scrooge and Marley. In his pursuit of money, Scrooge loses everything else, including the love of his life. In exchange, he grows old alone and despised. The same fate awaited Jacob Marley. Everyone in the film whose primary motivation is greed lives a mostly unhappy life and Scrooge, of course, is only able to avoid dying under the same circumstances by virtue of the visitations of the spirits.
It's Never too Late to Change
One can only assume that the Spirits of Christmas Past, Present and Yet to Come could have scared Scrooge into redemption at any earlier point in time. There is nothing to suggest that Marley had to die first in order for the other spirits to work their magic, but perhaps it was determined that Scrooge needed the shock of actually seeing for himself what lay in store if continued on as before. At any rate, by the time Scrooge welcomes the spirit of Christmas into his heart, behaves like a second father to Tiny Tim and earns a reputation for being "as good a man as the old city ever knew" he’s pretty old and definitely set in his ways. So, the message is definitely being sent that regardless of how old, set in your ways and just plain mean-spirited to those less fortunate than yourself you are, all it takes is one life-altering experience to completely transform you into something more closely revealing a normal human being.
A Society-Wife Call for Compassion
While A Christmas Carol has always appeared to be the story of a singularly unpleasant old skinflint, the repeated references to the treatment of London’s poor makes it fairly clear that Dickens was not limiting the lack of compassion toward those folks to Ebenezer Scrooge. The consequences of poverty are shown from beginning to end in the form of nearly everyone with whom Scrooge has contact. To drive the point home, one of the sights the Spirit of Christmas Present reveals to him is that Alice, the only woman Scrooge ever loved who broke off their engagement because of increasing obsession with money, tending to the poor and sick on Christmas Eve. It is likely the gregarious spirit's snarky echo of Scrooge's earlier words "Are there no prisons? Are there no workhouses?" that is the most memorable manifestation of his theme. What the story is asserts is that while Scrooge represents the extremes of those with no compassion toward the needy, anyone with the means to do something who chooses to look the other way is complicit in any economic system which fosters widespread poverty and suffering for some while others lives like royalty.
