In a word – yes, if you want to write a good hero story. Fear is a response to danger. It is a call to action. The action you take could be heroic or cowardly. That is where your light or dark side shows up. But fear is an instinctual response to danger and thank goodness! To be machine-like and not be able to respond with all the nuance of a human would be the end of us.
Fear tells us to push away from something that could harm us – it is the instinct to avoid pain, be it physical or psychological. The positive response to fear is to get tough, prepare, build your resources, fortify, strategize, collect metrics – reshape the world to produce a better outcome. This is the foundation of many hero movies. The dark response to fear is to deny, blame others, avoid, self-protect. Enter the coward. Put both in your screenplay and watch how the emotion builds. My favourite coward is Cypher from The Matrix.
Fear is the driving force in self-discipline which heroes need to develop in spades. They look at impending doom and decide to do whatever unpleasant task is required to change that outcome into something desirable. Heroes exercise that just-do-it anyway muscle, and it is a muscle. With practice s/he gets really good at it.
Delayed gratification is another crucial part of the fear-driven world. Some thing are only earned after doing the hard work. There is a famous marshmallow experiment where kids were told they could have a marshmallow now or two if they waited until a later time. Some kids couldn’t wait. (Incidentally they were not as successful in life). Putting in effort for something you want later is grounded in an ability to plan for the future. Placing yourself on a time line with a view of the past and the future is part of the fear driven world. When you can use the past and picture the future that you want, you can endure lessor pain now for a greater gain later.
The key when using the fear factor is to make sure everyone is really clear on the real consequences of failure and the rewards of success. The rewards have to outweigh the effort required.
In the face of fear we are also called to be self-sacrificing. Bravery in the service of others develops your self-esteem. The more agency we feel to push back the boundaries of our mortality, the more heroic we are.
These are the elements you want to put in a Hero story.