The Spirit of Fear
Most fears are actually selfishness. If you are not the center of the world, what are you afraid of? John says in 1 John 4:18, that fear has torment in it. The person who's thought life is constantly self centered and selfish will have inflated views of their own self worth and therefore constantly is concerned about their welfare emotionally, physically, financially, socially, etc... This can bring extreme anxiety and stress and can cause extraordinary mental instability.
There is a simple and yet profound remedy. Jesus said life is ultimately not about you. He said the way to a full life is to love God with all your heart, soul, and strength, and then to love other people like you love yourself. This kind of love strikes at the core of fear! Fear fades when real love shows up. The love of God put in our hearts (Rom. 5:5) by the Holy Spirit makes us live bigger than wanting security. Life becomes an adventure!