Now please turn over to John 1, verse 4. Christ, the eternal Word is Himself, the radiant splendor of God's glory. The biblical phrase light in the Lord signifies the source of light in life. The implied message is, if God is light, to come to God is to go to the light and to receive life.
As the predicted Messiah, Jesus was to be a light to the Gentiles as well. Christ declared Himself the light of the world, and as light He was God manifested in the flesh. Jesus as the Word is the eternal expression of God as a word is the expression of a thought. In the essence of His being God, Christ is the light of life.
Accordingly, Christ the Word manifested the attributes of the divine nature as life, love, and light. These are inseparable and constitute the glory which the disciples saw in Him. In revealing and giving life, Christ became the light of men.
Christ is a teacher, the enlightener, the guide, the Savior of humanity. He gives us light, that is, He gives us understanding, truth, and wisdom. So Jesus, as the One who brings the true knowledge of God, is the light of humanity. And when people tried to extinguish the light of men, darkness fell when Jesus was being crucified.
So the New Testament portrays Jesus as the personification of light, of divine illumination.