heart and soul vs in earnest

heart and soul

adv
  • With the utmost earnestness. 

noun
  • the core of a thing; the most essential or important part 

  • passion; true commitment 

in earnest

adv
  • Having a sincere intent. 

  • With considerable commitment, determination, or effect; significantly. 

adj
  • Sincere; determined; truthful. 

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