Good fear is when we live in the moment and react to the present situation. For example, wearing a helmet while riding a bicycle or avoiding getting hit by a car. We buckle our sear belts before driving in the car or use the brake to avoid an accident. Good fear is when we take actions in the present in a way that mitigates the risk from clear dangers in the present or near future.
Bad fear is when we think about something that is not close to us in space or time and our body reacts to what we’re thinking. We have words like worry, afraid, panic, concern and anxiety that we use to describe our reactions to bad fear. Bad fear is when someone obsesses daily on something that does not present a clear and present danger to them. Our bodies react to what we are thinking, our mind thinks something is wrong with our body, then our body reacts to what we are thinking and the cycle continues. Bad fear that builds over time is what leads to symptoms of anxiety and depression that mimic real medical issues.
Worrying about the national debt is bad fear. Good fear is taking actions (that are legal) in the present or near future to support reducing the national debt.