It is good when fear pushes you to act, run or fight, do something, do anything. It is bad when you get paralyzed.
Selco talks about how fear can be a great motivator based on his first hand experience when the SHTF in Yugoslavia.
Read it and then ask yourself, "What would I do?"
Could you do what is necessary to defend yourself?
Read the rest here and take note.
There will be a final exam when you least expect it.