Stick By Meaning

(idiomatic) to follow or adhere to somebody or something, to remain loyal and unswerving in one's attitude towards somebody or something

Example: 2008, Walking with the Word: Daily Ventures Into 15 Books of the Bible, by Larry Schats, page 12:
  To be loyal means to stick by someone and to prove yourself dependable and reliable. This is what Caleb does, and for that he is rewarded, despite his age of eighty-five.