christening vs rite of passage

christening

noun
  • Any instance of someone's or something's being christened. 

  • The Christian sacrament at which someone, usually a child, is baptized and given a Christian name. 

rite of passage

noun
  • A ceremony or series of ceremonies, often very ritualized, to celebrate a transition in a person’s life. Baptisms, bar mitzvahs, weddings and funerals are among the best known examples. 

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