A demoniac person believes in the strength of his personal work, not in the law of karma. According to the law of karma, a man takes his birth in a high family, or becomes rich, or very well educated, or very beautiful because of good work in the past. The demoniac think that all these things are accidental and due to the strength of one’s personal ability. They do not sense any arrangement behind all the varieties of people, beauty and education. Anyone who comes into competition with such a demoniac man is his enemy. There are many demoniac people, and each is enemy to the others. This enmity becomes more and more deep — between persons, then between families, then between societies, and at last between nations. Therefore there is constant strife, war and enmity all over the world.

From Srila Prabhupada’s purport to BG 16.6