Commentators unanimously agree that the root cause of fear is not the strength of the enemy, but forgetting God. The verse explicitly states, "and hast forgotten Jehovah thy Maker." Scholars like John Calvin note that "Maker" refers not only to God as the universal Creator but also as the one who spiritually regenerates His people. Forgetting God's immense power and His personal relationship with you inevitably leads to magnifying human threats.