1 John 5:18. "We know whoever is born of God does not keep on sinning. But whoever is born of God guards himself, and the wicked one cannot touch him." Satan cannot do anything to you apart from fear, any more than God will do something for you apart from faith (Heb. 11:6). Just as faith is unwavering confidence in God and His WORD, fear is unwavering confidence in something that has the ability to hurt you or cause a serious loss in your life. It is activated through words and actions in the same way faith is activated through words and actions.
The Fruit of the Spirit is love, joy, peace, patience, gentleness, goodness, faith, meekness, and self-control. Notice no fear.
Fear must come from the outside, it first comes against your mind as thoughts of doubt, unbelief, disaster. When you meditate on these and it starts to come out of your mouth, they begin to grow and take root inside you. Jesus said, "Out of the abundance of the heart the mouth speaks." (Matt 12:34, 25) If you want good things to come to pass in your life, speak God's WORD. Refuse to speak words of doubt, fear and unbelief which gives the devil a foothold. Don't ever act on fear. It will move into your spirit and choke your faith. It will do its best to stay there and ruin your life. Fill your heart with God's unchanging WORD, and watch the abundance of your heart produce the fruit of the Spirit, the blessings of God.