backslide vs turn back

backslide

verb
  • To regress; to slip backwards or revert to a previous, worse state. 

  • To revert back into a life of sin after being saved. 

  • To shirk responsibility; to renege on one's obligations or commitments. 

noun
  • A backward regression; a reverting back to a worse state. 

  • A dance move in which the feet are alternately slid back and the heels lifted, giving the illusion of walking forwards while actually moving backwards. 

turn back

verb
  • To return to a previous state of being. 

  • To cause to reverse direction and retrace one's steps. 

  • To reverse direction and retrace one's steps. 

  • To prevent or refuse to allow passage or progress. 

  • To adjust to a previous setting. 

  • To fold something back; to fold down. 

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