Humanity has come to fear the unknown. In most cases it's our own instinct for self-preservation. In the case of our ancestors, it made since because we didn't yet have the technology to defend ourselves from things that could kill us (early hominids weren't quite on the top of the food chain). Today that same instinct keeps us safe from other humans (mostly scam artists, thieves, and psychopaths) and the occasional swamp monster.
However, there are times when society and religion will generate fear. Ignorance is defined as a lack of knowledge about something. A catalyst of curiosity. Society has often turned to religion out of fear of ignorance, and their by quenching their own curiosity and replacing it with more fear (i.e. curiosity killed the cat). It leads to fearing curiosity, a fear of being hated or made an outcast for trying to see what's behind the curtain.
"Fear leads to anger. Anger leads to hate. Hate leads to the dark side"_YodaIt's okay to have a fear of the dark, as long as you master the fear. Be weary of your surroundings, but not of curiosity. Curiosity brings knowledge, and when we know whats lurking in the shadows, it becomes a lot less scary.