adherent vs true believer

adherent

noun
  • A person who has membership in some group, association or religion. 

adj
  • Adhesive, sticking to something. 

  • Having the quality of clinging or sticking fast to something. 

  • Attaching or pressing against a different organ. 

true believer

noun
  • One who believes dogmatically in something regardless of evidence or even conclusive proof that the thing is false or was staged; one who has true-believer syndrome. 

  • Used other than figuratively or idiomatically: see true, believer. 

  • A strict follower of a doctrine. 

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