What is a medieval literacy form where the story uses symbols and metaphors to show a profound moral or spiritual meaning

In my opinion, the correct answer is morality play. It is a theatrical genre that was supposed to fulfill the great function of art: to teach the audience about virtue and vice, justice and injustice, heaven and hell that await us. There were no characters that represented individuals and their lives; there were highly symbolical personified moral features, such as Justice, Beauty, Vice, Knowledge, etc. In their essence, these morality plays were a fusion between sacred and secular; they tried to impose religious messages while translating them to a language that laymen could easily understand, providing them guidance through life. One of the most representative morality plays (and characters) is that of the Everyman. He was supposed to show all the issues of a sinful, frail, and mortal human nature, as opposed to the timeless, spiritual, religious ideals.