In declaring himself to be the light, Jesus was claiming divinity. In the Bible, “light” symbolizes the holiness of God (see also Psalm 27:1; 36:9; Acts 9:3; 1 John 1:5). Jesus is not merely a light or another light, he is the one and only true Light. As the Light, Jesus illumines the truth, gives people spiritual understanding, and reveals to us God himself and what he has done for us.

In claiming to be the light of the world, Jesus defined his unique position as the one true light for all people, not just the Jews. Isaiah wrote, “I will also give You as a light to the Gentiles, that You should be My salvation to the ends of the earth” (Isaiah 49:6 NKJV).

Death brings eternal darkness; but to follow Jesus means to never walk in darkness, but … have the light of life. When we follow Jesus—accepting him as Savior and Lord and following him—we are walking in his light. We no longer walk blindly in our sin, rather his light shows us our sin and our need of forgiveness, guides us along life’s pathway, and leads us into eternal life with him. The psalmist said, “In Your light we see light” (Psalm 36:9 NKJV). 

Barton, Bruce B. John. Life Application Bible Commentary. Wheaton, IL: Tyndale House, 1993.