It is impossible for both faith and fear to exist together. One will be prevalent over the other, and ultimately win. If you are fearful, your mind is in turmoil. Fear controls you. One moment you may experience peace only to discover the next that it is gone. A thought invades your mind or a circumstance arises, and you discover you are on a roller coaster ride of faith and fear. You want to believe and trust God with all your heart. You want peace. You want to get off that roller coaster, but can find no exit.
God has made provision for you to overcome fear. If you exercise the mustard seed of faith which God has given, you can discover His peace when faced with circumstances over which you have no control. To have this peace you come to God “with no wavering (no hesitating, no doubting). For the one who wavers (hesitates, doubts) is like the billowing surge out at sea that is blown hither and thither and tossed by the wind. For truly, let not such a person imagine that he will receive anything [he asks for] from the Lord. [For being as he is] a man of two minds (hesitating, dubious, irresolute), [he is] unstable and unreliable and uncertain about everything [he thinks, feels, decides]” (James 1:6-8, Amplified). If you don't come to God with an unwavering mindset to believe God no matter what happens, fear defeats you. A person who is double-minded should not expect to receive anything from Him. If you are double-minded, there is no peace.
The purpose of the spirit of fear is to destroy your mustard seed of faith by making you feel “unstable, unreliable, and uncertain” about everything. It wreaks havoc on your thoughts, and weakens your faith in the promises of God. As a Christian you know you should trust in God's promises in His Word, and you do to a certain extent. However, your fears and doubts reveal that deeply-rooted within you are beliefs that are totally opposite to the promises of God. This is where you start to attack fear....by honestly opening and examining what you believe, and then allowing the Word and the Holy Spirit to change what needs to be changed.
You can be free of fear, and have peace. This is God's truth, and promise. Study God's Word. As you start to face and realize the beliefs within you that are contrary to what it reveals, you can apply His Word to your life. Faith begins to grow, and gains greater strength to defeat the spirit of fear within you that you have been unable to control. You don't have to be double-minded, unstable and uncertain. You can have God's peace and learn how to overcome your fears and your doubts. God's Word has the power to pull down these strongholds in your life. Learn His Word. Apply it to those areas that must honestly be examined. Pray and ask for God's help to do what seems impossible. It is not. All things are possible with Him. He is always available. Don't ever give up. You can be free of the spirit of fear.