Encouragement for Some or All? (James 5:1-6)

When James is warning the rich it is easy for us to say that it is the other people who have to worry.  We might think that we are not on the Fortune 500 list so in reality we are not that rich.  The truth is that as Americans we are very rich, very blessed, and among some of the most wealth in the world.  Can we be Christians then?  How can we have a joy in the Christian life when James tells the rich to “weep and howl”?  Are these verses for all Christians or just a select few Christians?