spiritual world vs unseen

spiritual world

noun
  • The afterlife. 

  • A metaphysical plane of existence parallel to the material world and occupied by spirits and other unearthly forces. 

unseen

adj
  • Unskilled; inexperienced. 

  • Not hitherto noticed; unobserved. 

  • Not seen or discovered; invisible. 

noun
  • An examination involving material not previously seen or studied. 

How often have the words spiritual world and unseen occurred in a corpus of books? (source: Google Ngram Viewer )