exorcise vs purify

exorcise

verb
  • To drive out (an evil spirit) from a person, place or thing, especially by an incantation or prayer. 

  • To rid (a person, place or thing) of an evil spirit. 

purify

verb
  • To free from guilt or sin. 

  • To cleanse, or rid of impurities. 

  • To become pure. 

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