Rudolf Otto was a German theologian who wrote a book called The Idea of the Holy.
He believed that when we experience something that is very powerful, we feel a special kind of feeling called “numinous”. Numinous is a feeling of mystery, awesomeness, and fascination all rolled into one.
When we experience something numinous, it can be so powerful that it almost seems like it is coming from a higher power. It can make us feel connected to something larger than ourselves. Otto thought that this experiencing of the numinous is what helps people understand and appreciate things like religion and spirituality.