nihilism vs unbelief

nihilism

noun
  • The rejection of, or opposition to, religious beliefs, (inherent or objective) moral principles, legal rules, etc., often due to the view that life is meaningless (sense 1). 

  • A doctrine grounded on the negation of one or more meaningful aspects of life; in particular, the view that nothing in the world actually exists. 

  • The rejection of non-proven or non-rationalized assertions in the social and political spheres of society. 

  • A delusion that oneself or the world, or parts thereof, have ceased to exist. 

  • Something that is regarded as meaningless. 

  • The view that all endeavours are devoid of objective meaning. 

unbelief

noun
  • An absence (or rejection) of belief, especially religious belief 

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