Paul Walker said "I'm not afraid of anything. That's just the way I am." And that's why he died at age 40 in a fiery car wreck instead of dying at age 65 or later of old age.
You're using an isolated Bible quote without giving us the context of that quote. When I looked up Matthew 28:20 in the King James Bible, I got "Teaching them to observe all things whatsoever I have commanded you: and, lo, I am with you always, even unto the end of the world. Amen." The two verses in that chapter that did mention fear where when the angel told the two women coming to see Jesus in his tomb not to be afraid of him (Matthew 28:5) and when Jesus told the two women not to be afraid of him (Matthew 28:10). You seem to be interpreting the phrases "Fear not ye" and "Be not afraid" as meaning that you should not be afraid of anyone or anything at any time, when in actuality what the angel and what Jesus said was much narrower in scope. The angel guarding Jesus' tomb did not want the women approaching the tomb to be afraid of him. Neither did Jesus. Also, there are many quotes in the Bible saying you should be afraid of God:
https://www.kingjamesbibleonline.org/Bible-Verses-About-Fear-Of-The-Lord/
Fear is often mocked and ridiculed in our world, but a moderate amount of fear has value. Fear keeps you from making bad choices. Fear helps you keep your priorities more clearly in focus. Our jail cells, hospital beds and cemeteries are filled with people who were not afraid of things they should have been afraid of.