Probably one of the more profound and helpful things I have read on fear…
“There is no fear in love; but perfect love casteth out fear.” Fear is the painful emotion that arises at the thought that we may be harmed or made to suffer. This fear persists while we are subject to the will of someone who does not desire our well-being. The moment we come under the protection of one of good will, fear is cast out. A child lost in a crowded store is full of fear because it sees the strangers around it as enemies. In its mother’s arms a moment later all the terror subsides. The known good will of the mother casts out fear.
The world is full of enemies, and as long as we are subject to the possibility of harm from these enemies, fear is inevitable. The effort to conquer fear without removing the causes is altogether futile. The heart is wiser than the apostles of tranquillity. As long as we are in the hands of chance, as long as we look for hope to the law of averages, as long as we must trust for survival to our ability to outthink or out maneuver the enemy, we have every good reason to be afraid. And fear hath torment.
To know that love is of God and to enter into the secret place leaning upon the arm of the Beloved – this and only this can cast out fear. Let a man become convinced that nothing can harm him and instantly for him all fear goes out of the universe. The nervous reflex, the natural revulsion to physical pain may be felt sometimes, but the deep torment of fear is gone forever. God is love and God is sovereign. His love disposes Him to desire our everlasting welfare and His sovereignty enables Him to secure it.”
The Knowledge of the Holy by A.W. Tozer p. 154