obedience vs observance

obedience

noun
  • The quality of being obedient. 

  • The collective body of persons subject to any particular authority. 

  • A written instruction from the superior of an order to those under him. 

  • Any official position under an abbot's jurisdiction. 

observance

noun
  • Reverence; homage. 

  • The practice of complying with a law, custom, command or rule. 

  • That which is to be observed. 

  • Observation or the act of watching. 

  • A rule governing a religious order, especially in the Roman Catholic church. 

  • The custom of celebrating a holiday or similar occasion. 

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