Be good, and learn!
There are many ways to have healthy self-esteem. Most agree that there are two broad components to self-esteem: (1) the view that I am a worthwhile or good person; and (2) the view that I have some competence (i know things or know how to do things).
If people continue to strive to be virtuous or good and to learn and develop skills they will tend to have a positive self-concept. Striving is key.