One of the reasons missions is at the heart of Christianity is that Jesus teaches us to see the world utterly differently that we ordinarily see it. If you simply view the world the way it is seen in television and secular media and public education and theater, missions will make no sense and be no part of your life. In fact, I would say that if you want to see how much the secular culture shapes and controls you, simply ask how great your burden is for missions. The only way to have a burden for missions is to be more influenced by Jesus than by the American culture. To see the world the way Jesus sees it.
—John Piper
Vision for the Harvest: 2000 by 2000
Related: Passage for February from the 2008 Desiring God Calendar.