Haunted houses, ghosts, demons—our Western culture can’t seem to get enough of the spirit world. The latest Gallup poll indicates that 42% of Americans believe in demon possession, 37% believe in haunted houses, and 32% believe in ghosts. (Not just Americans are enthralled—40% of the British believe in haunted houses, too.) Though interest in the paranormal is widespread, the majority of people are skeptical. They discount all spirit activity, going so far as to deny the existence of Satan and demons. Atheists stated this view succinctly in a sign they planted next to a manger scene last Christmas at the...