Here, "두려움" or "fear" is personified. It is "talking" to the speaker, telling him he/she must not stop striving to become a better person. A fairly commonly used expression in the given sentence, "생긴 대로 살아서는 안 된다", literally means that "one should live in a manner that conforms to how one looks." Of course (like many other proverbs and expressions directly translated from Korean to English), without understanding its underlying meaning, the expression does not make much sense.
What the expression suggests is that individuals should not let their looks define who they become or influence how they lead their lives. Depending on different contexts, one could also interpret it as saying that individuals must aspire to be ambitious, to be larger-than-life, to achieve bigger things in life no matter how little or insufficient the resources they are endowed with are. (Put it rather crudely and just to aid your understanding, "dream big! No matter how unattractive you are!")
Your sentence seems to suggest, "fear taught me (or "told me" if you want to more literal translation) to never let my look define how I live my life (or who I become) and to never stop endeavouring/striving/trying/aspiring to become a better person."