‘I Am the Light of the World’
The Apostle John has one overriding desire, and that is to bring people to faith in Christ; that, through the witness of his gospel, his readers would believe three essential things about Jesus: (1) that he was the Christ [the Jewish Messiah]; (2) that he was the Son of God [more specifically and radically he was God the Son, the third person of the Trinity, come in the flesh]; and (3) that by believing, they'd receive eternal life. With this goal in mind, John selected specific teachings and miraculous works of Jesus that he thought would best communicate these convictions to his readers. There are seven discourses included in this material that are built around self-identifying statements made by Jesus and they're all structured the same. They open with the verb of being, 'ego eimi' (I am), followed by a metaphor, the second of which is 'I am the light of the world' (Jn.8:12)'.
This statement was made by Jesus, probably on the last day of the Feast of Tabernacles. During this celebration, there was a lamp-lighting ritual that Jesus uses as a reference point for making this self-identifying statement. The statement is provocative - “I am the light of the world. Whoever follows me will not walk in darkness, but will have the light of life.” The Pharisees reject his statement by claiming it untrue. But Jesus defends the integrity of his testimony on two grounds: first, on the grounds of who he is; and second, on the grounds of Jewish law. His first argument is made by way of inference - “...I know where I come from and where I am going,...(Jn.8:14).” The inference is that he transcends time and this dimension of space. He existed prior to his incarnation. He came from one realm into another, and could do this because he's 'God the Son'. Another statement that suggests the same thing more directly is - “Truly, truly, I say to you, before Abraham was, I am (v.58).” What Jesus is literally saying is that he existed before Abraham came into being. This claim was so disturbing to the Jews that they picked up stones to throw at him (v.59). Then, in v.18 of John 8, Jesus says that 'God the Father' corroborates his testimony - “...the Father who sent me bears witness about me.” So his testimony doesn't stand alone, but rather, conformed to Jewish law, which required two witnesses to establish the truthfulness of a claim. Jesus truly is the 'light of the world', but what does the metaphor mean?
Light refers to spiritual and moral understanding. Jesus is the one who enables us to see clearly, both spiritually and morally. He exposes the truth about man and his sinful condition, and he reveals how God has addressed our desperate spiritual need. In order, then, to move from spiritual error to true spiritual understanding, we must come to Christ in faith - “...Whoever follows me will not walk in darkness, but will have the light of life (v.12).” The verb 'follows me' is in the present tense, indicating continuous following (“keeps on following me”); he will not live in spiritual error; but, rather, he will possess 'the light of life'. These followers of Christ will receive, as their possession, eternal life! Faithfully following Christ gives birth and shape to a particular kind of life, a life formed by true fellowship with God and an ever-developing spiritual and moral vision.