"God said, 'Let there be light'. And there was light. God showed His people where to go with a cloud in the daytime and a tower of fire in the nighttime so that they always knew which way to go. God is the creator of light and every gift that comes from Him is good and perfect. God is light and there is no darkness or changing in Him. I won't be afraid, because God is my light and my salvation. I don't need the sun or the moon--God will be my everlasting light and glory. God is the fountain of life and light. God commanded the light to shine out of darkness. God turns on the light. He shines in the darkness.
The Bible is a light. The Bible shows me where to go and makes me wise.
God showed us His light when He gave us Jesus. Stand up and shine! Jesus, our light, has come! The people sitting in the dark can now see light because of Jesus! Jesus is the light of the world. If I follow Jesus, I will never walk in darkness because I will have the light of life. I must walk in God's light, that way I will be clean from all wrong.
I am a light in the world. I will not hide my light but I will let my light shine so that everyone can see the light of God in me."
(References: Gen. 3:3; Ex. 13:21; James 1:17; Psalm 27:1; Psalm 18:28; Psalm 119:105; Psalm 36:9; Is. 60:19; 2 Cor. 4:6; Is. 60:1; Is. 9:2; John 8:12; 1 John 1:7; Matt. 5:14)
This passage is a bit more abstract for the kids, but they do a good job repeating back the phrases to us... and I think the fact that "God is light!" stays very clearly in their minds. :)