Greed and envy: two sides of the same coin

"I don't like to see people treated like cattle," said [Commander of the Night Watch, Samuel] Vimes....  "And of course that's what you've always done, isn't it...?   Power over little people. That's what vampires want.  The blood is just a way of keeping score...."
"You are in favour of the common people?" said Dragon [King of Arms, who is also a vampire] said mildly.
"The common people?" said Vimes. "They're nothing special. They're no different from the rich and powerful except they've got no money or power.  But the law should be there to balance things up a bit.  So I suppose I've got to be on their side."

Terry Pratchett, Feet of Clay

Inciting envy - AnotherThink
A system based on greed, or to put it more kindly, on improving one's lot in life, in no way rules out the possibility that I can freely choose to give away some or all of my wealth to help others. In other words, if greed plays a part in my internal motivations to get ahead, my conscience might still be pricked to consider the poor, moderate my greedy ways and share what I have with others. And, in fact, many Americans do just that.

My response (awaiting moderation):

While you are correct in pointing out that envy is a sin, your rationalization of greed tells only half the story.  There is no "kind" way to describe greed and it is more than simply wanting to "improv[e] one's lot in life", for it is possible to achieve such a goal without greed.  The two- greed and envy- arise from the same impulse to treat things as more important than one's fellow human beings (envy, by wanting to take chat which does not pertain to one's self; greed, by hording goods while the basic needs of others go unmet).  Furthermore, you give no reason why, if one can moderate one's greed, why one can't also moderate one's envy as well.  Finally, what you call "envy", others might term "social justice", and this may be one of those times when the truth might lie somewhere between these two poles.
But I will agree that simply changing the system isn't going to make a dent in the problem unless and until there is a similar change in people's hearts.  I would even go one step further: the latter change renders the former inconsequential, for where everyone truly loves his or her neighbor as one's self, it wouldn't matter whether the system is capitalist, communist, or otherwise.

@ Susan ("Also, as an aside, I keep hearing how there's hunger in this country, yet we're all obese and at risk for heart disease, etc. Story one says kids are hungry; story 2 says they are fat!! What does it mean?!?")

It means that some kids are overweight and others go hungry.  The two are not mutually exclusive.

In the end, I think the important thing isn't to be on the side of the rich or the poor, but on the side of who's right.