"a beautiful sermon about the Witch of Endor, and the perils of them that meddle wantonly with the unseen Powers"

The Witch of Endor
Public DomainThe Witch of Endor - Credit: Nikolaj Nikolajewitsch

The Witch of Endor was called upon by King Saul to summon the ghost of the recently deceased prophet Samuel, in the Bible. 

Samuel’s ghost is furious at being roused from the netherworld, and berates Saul for disobeying God. He predicts the downfall of Saul and his army in battle the next day, and that Saul and his sons will join him in the abode of the dead. The next day, Saul’s army is indeed defeated, and Saul commits suicide after being wounded.