Question: "What does it mean that Jesus is the true light (John 1:9)?"
Answer: The apostle John opens his Gospel with a systematic, 18-verse introduction to the Lord Jesus Christ. A key aspect of Christ’s nature that John highlights is that He is the bearer of light. Jesus brings the revelation of God’s life and light into a dark world (verses 4–5). In John 1:6–9, the apostle explains that John the Baptist was merely a witness to the light, but Jesus is the true light: “There was a man sent from God whose name was John [the Baptist]. He came as a witness to testify concerning that light, so that through him all might believe. He himself was not the light; he came only as a witness to the light. The true light that gives light to everyone was coming into the world.”
John the Baptist’s message was illuminating, but he was not the true light. Jesus is the true light, the real thing, the genuine article—God in the flesh. He alone reveals God’s glory in the world because He is God incarnate who “became flesh and made his dwelling among us. We have seen his glory, the glory of the one and only Son, who came from the Father, full of grace and truth” (John 1:14; see also 1 Timothy 3:16; 1 John 1:1–2; 4:2).
By stating that Jesus is the true light coming into the world, John directly connects Him to Israel’s Messiah as the prophets foretold: “The people walking in darkness have seen a great light; on those living in the land of deep darkness a light has dawned” (Isaiah 9:2; see also Isaiah 49:6; 60:1–2; Malachi 4:2).
Jesus is “the radiance of God’s glory and the exact representation of his being” (Hebrews 1:3). He beams forth the light, truth, and life of God to the world and into the hearts of men and women. Jesus Himself declared, “I am the light of the world. Whoever follows me will never walk in darkness, but will have the light of life” (John 8:12; see also John 9:5). At Christ’s transfiguration, Peter, James, and John caught a glimpse of the true light as Jesus’ “face shone like the sun, and his clothes became as white as the light” (Matthew 17:2). In the book of Revelation, John describes Jesus’ face “like the sun shining in all its brilliance” (Revelation 1:16). He is the “bright Morning Star” (Revelation 22:16).
Jesus is the true light of God for those who partake of His salvation. When we receive Jesus Christ as Lord and Savior, He makes God’s “light shine in our hearts” so we can “know the glory of God that is seen in the face of Jesus Christ” (2 Corinthians 4:6). Those who trust in Jesus and “believe in the light” become “children of light” (John 12:35–36, 46). As children of the light, we are called to bring His “salvation to the ends of the earth” (Acts 13:47). Jesus said, “Let your light shine before others, that they may see your good deeds and glorify your Father in heaven” (Matthew 5:16).
Several elements are necessary to sustain human life: light, air, water, and food are among the most critical. Jesus is the true light means He is our essential source of life. Without light, it is impossible to sustain life of any kind on earth. If the sun ceases to shine, everything will die. Not only is Jesus our light, but He is also the spiritual air we breathe. By His Holy Spirit, He breathes on us the “breath of life” (John 3:8; 20:22). Jesus is also the “living water” who, by His Holy Spirit, becomes in us “a spring of water welling up to eternal life” (John 4:10–14; 7:37–39).
Jesus declared Himself to be “the true bread from heaven” (John 6:32). He is the genuine “bread of life” (John 6:35). He is our life-giving, life-sustaining source. He fully meets all our needs and perfectly satisfies our souls. In John 15:1–17, Jesus revealed that He is “the true vine,” and His Father owns the garden. Christ’s followers are described as fruit-bearing branches. They are the true believers who “abide in the vine.” Jesus is everything we need for life because He is God, “the fountain of life” (Psalm 36:9).
Jesus is the true light is John’s unequivocal way of stating that Jesus Christ is the ultimate, one and only, genuine self-disclosure of God to man. The Word of God became flesh and blood, and Jesus Christ is “the light of the world.” In Him, there is “no darkness at all” (1 John 1:5). His light is our “light and our salvation” (Psalm 27:1). Jesus Christ is the true light of God sent into the world to pierce through the darkness. Through His life, ministry, and message, Jesus brought the light and life of God to bear on everyone He encountered. That light continues to shine on earth through His Church (Ephesians 5:8; Philippians 2:15).