Jesus claimed, “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).
Jesus spoke that statement at the end of the Feast of Tabernacles (first mentioned in 7:2). The week-long feast included (among other things) daily lighting rituals that involved tall lamps standing in the temple courts. Using exaggeration, it was said that the glowing lights lit up all of Jerusalem.
Because of the current feast, Jesus made a claim coinciding with its lighting ritual. While the lamps only lit up the temple grounds, Jesus said “I am the light of the world.” The revelation of Christ was intended for more than just Jerusalem. The light of Christ dawned upon all creation (John 1:9).
After making his claim, Jesus promised, “Whoever follows me will never walk in darkness.” Here’s why that statement is significant: the lighting ritual during the Feast of Tabernacles remembered the pillar of fire by night that led the Israelites in the wilderness. God’s presence was with the Israelites in a visible way, a pillar of fire. And, when the pillar of fire moved, the Israelites followed it. The pillar of fire guided them.
Do you see the significance of Jesus’ statement, then? “Whoever follows me” draws on the image of the Israelites following the pillar of fire. Jesus is claiming to be the presence of God among them, and he is their guide. Only he has (and is) the way of life (John 14:6), and they must follow him like the Israelites followed the fire, if they wish to have the light of eternal life. Otherwise, they will live in darkness.
One other point: it seems that one of the agendas in John’s Gospel is to present Jesus as the fulfillment of Old Testament hopes, expectations, practices, institutions, and people. For example, up to this point in the Gospel, Jesus is Jacob’s ladder bridging heaven and earth (1:51), Jesus is the new temple that will be destroyed and raised three days later (2:19, 21), Jesus must be lifted up like Moses lifted up the snake in the wilderness (3:14), Jesus provides water that is superior to what is found in Jacob’s well (4:13-14), Jesus acts with divine prerogatives on the Sabbath (5:11, 17-18), Jesus brought about a miraculous feeding superior to the provision of manna in the Old Testament wilderness wandering (6:31-33), and Jesus claimed to be bread from heaven that would satisfy the eater forever, unlike the manna which was temporary in its purpose (6:35).
So when Jesus claims to be the light of the world, he is pulling the significance of the Feast of Tabernacles toward himself. Only Jesus shows the true meaning for such a feast. To reject the Light of the World and continue setting up lamps in the temple courts for one week a year is meaningless. Why? Jesus is the fulfillment of the feast!
In summary, then: (1) Jesus’ claim to be the light of the world should be interpreted against the background of the Feast of Tabernacles; (2) Jesus’ claim to be the light of the world is significant, since the lights in the temple grounds only lit up a limited region of the temple grounds–Christ’s light knows no limits; (3) Jesus’ words about people following him allude to the Israelites following the pillar of fire by night; (4) as a light greater than the pillar of fire, Jesus is the presence of God among them and the guide for his people; (5) Jesus fulfills the Feast of Tabernacles.