We know Jesus is the light of life because He fulfills the prophecies of the Old Testament and illuminates the path to salvation.
Jesus being called the light of life is rooted in His fulfillment of Old Testament prophecies concerning the coming of a savior. For instance, Isaiah 9:2 speaks of a great light that would shine on those in darkness. In John 1, we learn that He is the life and that this life is the light of men. As the incarnate Word, Jesus reveals the character and will of God to humanity. This light offers revelation of sin and guidance through the gospel, showing that Christ's purpose is to draw His people out of the darkness of sin into the marvelous light of His presence.
Scripture References:
John 8:12, Isaiah 9:2, John 1:4-5
Commentary