religion vs skepticism

religion

verb
  • Engage in religious practice. 

  • To make sacred or symbolic; sanctify. 

  • Indoctrinate into a specific religion. 

noun
  • Rituals and actions associated with religious beliefs, but considered apart from them. 

  • Any practice to which someone or some group is seriously devoted. 

  • Belief in a spiritual or metaphysical reality (often including at least one deity), accompanied by practices or rituals pertaining to the belief. 

  • A particular system of such belief, and the rituals and practices proper to it. 

  • The way of life committed to by monks and nuns. 

skepticism

noun
  • Doubt or disbelief of religious doctrines 

  • The practice or philosophy of being a skeptic. 

  • The doctrine that absolute knowledge is not possible 

  • A studied attitude of questioning and doubt 

  • A methodology that starts from a neutral standpoint and aims to acquire certainty though scientific or logical observation. 

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