believe in vs rely on

believe in

verb
  • To have confidence in the ability or power of. 

  • To believe that (something) is right or desirable. 

  • To ascribe existence to. 

rely on

verb
  • To be confident in. 

  • To be dependent upon. 

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