Fear is a natural emotion. All babies are born with only two fears: the fear of falling, and the fear of loud noises.
All other fears are learned responses, brought to the child by its environment, taught to the child by its parents.
The purpose of natural fear is to build in a bit of caution. Caution is a tool that helps keep the body alive.
It is an outgrowth of love. Love of Self.
Children who are made to feel that fear is not okay—that it is wrong to express it, and, in fact, that they shouldn't even experience it—will have a difficult time appropriately dealing with their fear as adults.
Fear that is continually repressed becomes panic, a very unnatural emotion.
People have killed because of panic. Wars have started, nations have fallen.