An escaped slave, a mother, when confronted with the possibility that her children would have to go back and live the life of a slave, did what we now feel is the unthinkable. It was painful watching Beloved, because the life of the main character, Sethe, was explicitly painful. But the experience drove her crazy. She was forever wounded and broken by the abuse of the experience of slavery. The terrible legacy literally haunted her and her surviving children.
Abuse can frequently be the door that lays a person open to the seduction of the demonic.
Sethe, out of her guilt. Denver, out of her isolation. Paul D, who at first resists and fights against it, is later seduced by Beloved. Finally, it is the church women of Sethe's community, that come, armed with their faith in God, to pray to God for the release of this family. Perhaps, if this were a Christian story, we would see the redemption of the characters in clearly spiritual terms.