How you think determines your reality. If your first inclination is to see the world darkly, you are going to live in a dark world. If your habit is to zoom in on what is wrong with a person, an idea or a thing, the world is not going to be a satisfying place for you. You may think you are simply being realistic, intelligent or discriminating, but you are actually stuck with a warped view of the world. Negative thinking is bad for your health, your relationships and your spiritual life.