Puritan John Flavel goes on to discuss why Christians have sinful fear. I will share four things we are ignorant of that make us afraid.
We are ignorant of God -- his "Almighty Power, vigilant care, unspotted faithfulness,and how they are all engaged, by covenant, for his people."
A second cause is ignorance of men; we "over-value" them. We forget that they can only do to us what God allows and that "it is usual with God to cramp their hands, and clap on the bands of restraint upon them, when their hearts are fully set in them to do mischief."
Third, we are ignorant of ourselves and our relationship to God. Assuredly, we are VERY DEAR to him, but we doubt it often.
In a time of bloody persecution Tertullian said to the Christians: "Art thou afraid of a man, O Christian! when devils are afraid of thee..." And Flavel says "O that we could, without pride and vanity, but value ourselves duly, according to our Christian dignities and privileges, which, if ever it be necessary to count over and value, it is in such times of danger and fear, when the heart is so prone to dejection and sinking fears."
Fourth, we are ignorant of our dangers and troubles. We fear that there will be no comfort in the danger and no escape from it. I can't do better than quote Flavel on it: "There is a vast odds betwixt the outward appearance and face of trouble, and the inside of it; it is a lion to the eye at a distance, but open it, and there is honey in the belly. Paul and Silas met that in a prison which made them to sing at mid-night, and so have many more since their day."
These truths put steel in the Christian and can carry us in the times we are filled with fear and tempted to turn back. Maybe these choice truths will induce you to read the Puritans on your own. I have never regretted doing so. The Puritans trembled at God's Word. Drinking from them is drinking very close to the source of the stream.