Young children sometimes know fear at night even if they are not sure what the darkness holds. Adults can also fear the darkness because they do know what may lay in wait. The answer for both is the wonder that is taught in Psalm 139.
There is nowhere anyone can flee, physically or mentally, from the presence of God. God is there and he holds us securely in his right hand. This blessed reality makes even the darkness full of the light of our Savior. Live it before your children. Live life in the light of your Savior. He is always there!
Psalm 139:7-12
Where can I go from your Spirit? Where can I flee from your presence? 8 If I go up to the heavens, you are there;if I make my bed in the depths, you are there.9 If I rise on the wings of the dawn,if I settle on the far side of the sea,10 even there your hand will guide me,your right hand will hold me fast. 11 If I say, “Surely the darkness will hide me and the light become night around me,”12 even the darkness will not be dark to you; the night will shine like the day,for darkness is as light to you.