"...you will call your walls Salvation and your gates Praise. The sun will no more be your light... for the Lord will be your everlasting light, and your God will be your glory."
“God is light,” says John in his first letter. That is the essence of His being. The totally pure God can have no darkness in Him. The created light of Genesis 1 is a mere reflection of God the Light.
So Jesus called Himself “the light of the world.” But He also reminded His disciples that they were “the light of the world” (Matthew 5:14). He wasn’t giving a command; He was making a statement of truth. Because we have Christ living in us by His Spirit, His light shines out of us as we seek to follow Him. We are a city set on a hill so that others can see the light of God in us. Our light will shine into dark corners of the places where we live, bringing God’s clarity and perspective.
From our fallen human viewpoint, the fact that we are the light of the world can sometimes seem unrealistic to us. When there is so much darkness around us, it is hard to believe that our humble lives could even make a difference. But we must rely on the fact that Jesus affirms that we are light because He is our everlasting light.
To be light to the world we need to be taking in regularly the Word which is "a lamp to my feet and a light for my path" (Psalm 119:105).