Dwight L. Moody once told the fable of an eagle who was envious of another that could fly better than he could. One day the bird saw a sportsman with a bow and arrow and said to him, “I wish you would bring down that eagle up there.” The man said he would if he had some feathers for his arrow. So the jealous eagle pulled one out of his wing. The arrow was shot, but it didnt quite reach the rival bird because he was flying too high. The first eagle pulled out another feather, then anotheruntil he had lost so many that he himself couldnt fly. The archer took advantage of the situation, turned around, and killed the helpless bird.
Moody made this application: if you are envious of others, the one you will hurt the most by your actions will be yourself.