Steven Pressfield said this quote

“ Fear is good. Like self-doubt, fear is an indicator. Fear tells us what we have to do. Remember our rule of thumb: The more scared we are of a work or calling, the more sure we can be that we have to do it. Resistance is experienced as fear; the degree of fear equates to the strength of Resistance. Therefore the more fear we feel about a specific enterprise, the more certain we can be that that enterprise is important to us and to the growth of our soul. That's why we feel so much Resistance. If it meant nothing to us, there'd be no Resistance. ”