One of my favorite things about summer is that it stays light out longer. I enjoy being able to be outside in the evenings, either going for a walk or even just having light streaming into the house. It makes sense to me that God refers to his kingdom as one of light. God has rescued us from darkness and brought us into the light. While we live on earth we will experience times of darkness. Literally ranging from the darkness outside that seems so long in the winter months, to the dark seasons in our lives that can be personal and painful. But we can have great confidence that as children of God we no longer belong to the kingdom of darkness, but now (here on Earth) and forever (in Heaven) we belong to the Kingdom of Light. We've been rescued from the darkness, purchased by the blood of the Son and forgiven by the Heavenly Father that is the Light of the World.
Colossians 1:11-14 We also pray that you will be strengthened with all his glorious power so you will have all the endurance and patience you need. May you be filled with joy,[a]12 always thanking the Father. He has enabled you to share in the inheritance that belongs to his people, who live in the light. 13 For he has rescued us from the kingdom of darkness and transferred us into the Kingdom of his dear Son, 14 who purchased our freedom[b] and forgave our sins.