Here I revised an old post with 7 thoughts about the psychology of some issues.
Unconsciously, people exposed to disgusting stimuli want to wash their hands. It is no surprise that some forms of sexuality were labeled dirty or filthy. Perhaps All Saints Day is an important "clean up" event following some Halloween activities.
Disgust and Morality- Learn more about the psychological foundations of Sanctity and Degradation based on research on the basic human response of disgust and the work of psychological scientist, Jonathan Haidt and colleagues.
Macbeth effect- Learn more about the need to cleanse oneself following an impure or unethical act. It's part of human nature. Here's one link. You will find more studies on moral purity in the research literature. Here's an npr story featuring psychological scientist, Spike W S Lee
Christians are divided about Halloween and other matters. Read more about the divide and how we can bring people together by respecting different perspectives.