Ytlayol-The Poem Riddles Volume 3

If you are me you would never stab a friend in the back; I am what a mother bear is to her cubs, while they are still whelping; You display me when you stay at a lesser paying job that gave you a start, when a higher paying job seeks you; I am what your father is to your mother if he has never cheated on her and has always been there for her; No matter how much money you try to spend on me, you'll never really be able to buy me; I am harder to find than a winning lottery ticket that says "I'm a winner, please try me"! Who am I? I am Loyalty.