How much pain and suffering is derived from our striving in all of its forms? James reminds us to set our hearts on things of eternal rather than temporal value. To quote a good friend of mind: the best things in life aren't things.
Jesus teaches us to "sent our hearts on the things above". St. Paul tells us to forget what lies behind press on to the upward call of God in Christ Jesus. C.S. Lewis quipped that if we set our hearts on the things of earth in the end we get nothing but if we set our hearts on the things of heaven we get earth thrown in. We live in a consumer focused, materialistic culture. I often wonder how many times in my life have I intentionally or unintentionally done damage to others simply because I wanted something I did not have.
The balance to the above paragraph is a realization that all good gifts come from God. The Bible plainly and consistently teaches that God pours gifts in our lives and blesses us with material things. We are told to enjoy the vineyard we have planted, we are told to be good stewards of the resources we have. I believe the difference has to do with coveting. When I submit to the lust of attaining and hoarding and accumulating whatever my focus has become God to me. When I covet something belonging to another I devalue what I do have. When I want you car . . . what's wrong with the car God gave me? When we covet our neighbors spouse our house or material thing -- we immediately devalue our own. Out of that frustration comes anger, violence and profound discontent.
Verse 11 -- never speak evil of another. We are not the judge of humanity. Wesley said we "think and let think". How do we engage in conversation without demonizing those who disagree with us? How do we help another discover the grace of God without standing in judgment over them? In the movie Rudy the Notre Dame priest says to young Rudy "in my many years as a priest I have arrived at two incontrovertible facts. There is a God and I am not He."