The 'fear' here is not terror but reverential awe — a constant awareness of and submission to God. This produces happiness, not anxiety. Its opposite is a hardened heart: the person who stops being sensitive to God's voice, who numbs themselves to conviction and correction. A hardened heart is always a prelude to a fall.
Memory phrase: Fear God. Stay soft-hearted.
Talk about it: What does it mean to have a hard heart? Why is that dangerous?
Prayer: God, help my heart stay soft and always honour You.