knock on wood vs please God

knock on wood

intj
  • Hopefully; a self-directive to undertake the customary action to ward off bad luck. 

verb
  • To take a customary action to ward off some misfortune that is believed to be attracted by a presumptuous statement. 

please God

intj
  • If it pleases God; God willing. 

How often have the words knock on wood and please God occurred in a corpus of books? (source: Google Ngram Viewer )