avowal vs confession

avowal

noun
  • An open declaration of affirmation or admission of knowledge. 

confession

noun
  • The open admittance of having done something (especially something bad). 

  • A formula in which the articles of faith are comprised; a creed to be assented to or signed, as a preliminary to admission to membership of a church; a confession of faith. 

  • A formal document providing such an admission. 

  • The disclosure of one's sins to a priest for absolution. In the Roman Catholic Church, it is now also termed the sacrament of reconciliation. 

  • Acknowledgment of belief; profession of one's faith. 

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