People scoff at the idea of demons and devils. Often they are seen as metaphors or perhaps superstitious explanations for unexplained events. Such thinking makes us vulnerable to their manipulations.
What are their manipulations? Anything that gets us to divide against one another. We are stronger together, so the Devil and his minions seek to isolate us. They give us self-doubt and prejudices that keep us from connecting with others. They make us feel unworthy and untrusting. They focus on our faults and the faults of others, playing on our insecurities.
God asks us to unite—to love and care for one another (including ourselves). Why do we so often listen to the divisive voice of the Devil rather than the loving Word of God?