You will keep him in perfect peace, whose mind is stayed on You, because he trusts in You.—Isaiah 26:3
The only fear I have is to fear to get out of the will of God. Outside of the will of God, there's nothing I want, and in the will of God there's nothing I fear, for God has sworn to keep me in His will. If I'm out of His will, that is another matter. But if I'm in His will, He's sworn to keep me.
And He's able to do it, He's wise enough to know how to do it and He's kind enough to want to do it. So really there's nothing to fear.
I get kidded by my family and friends about this, but I don't really think I'm afraid of anything. Someone may ask, "What about cancer? Do you ever fear that you'll die of cancer?" Maybe so, but it will have to hurry up, or I'll die of old age first. But I'm not too badly worried because a man who dies of cancer in the will of God, is not injured; he's just dead. You can't harm a man in the will of God. Success and the Christian, pp. 80-81.