Why are Fear Spirits so expert at what they do?

Some things in life are so simple and yet so profound that we overlook the real truth behind them. Take for example the effectiveness of fear spirits operating to disrupt our lives by causing us to be afraid. It never occurred to me that "fear spirits" are themselves full of fear. These spirits really fear punishment and their future and for good reason. Then it struck me: that is why they are so expert at their jobs of causing fear in us: that is their destiny not ours. The children of God have nothing to fear. If God our Father is for us, who can be against us?