The light of the world and the 'I am': Jesus and the children of Abraham

John's Gospel names no author. The final chapter says that the disciple whom Jesus loved wrote these things down (21:24), and from the second century the church identified him with John the son of Zebedee. Scholars such as Carson and Morris still defend this, while Richard Bauckham argues for John the Elder and others for a Johannine school. The date is usually about AD 85 to 95, with some arguing for an earlier one. John writes so that readers may believe that Jesus is the Christ, the Son of God, and have life (20:31). The long arguments of chapter 8 are not found in the Synoptic Gospels, though their themes, such as Jesus' authority, his relation to the Father and the response of the leaders, run through all four. The Synoptic Gospels also record sayings of Jesus about children of Abraham (Matthew 3:9; Luke 3:8; 13:28) and about the cost of rejecting the prophets.

The chapter belongs to Jesus' visit to Jerusalem for the Feast of Tabernacles (chapter 7), though the feast is not named again. The words 'I am the light of the world' were probably spoken at the treasury, in the Court of the Women, where the Mishnah says great lamps were lit during the feast (the Mishnah is a later source, so this is a likely setting rather than a certain one). Light also recalled the pillar of fire that led Israel in the wilderness (Exodus 13:21).

The first section requires a note. The story of the woman caught in adultery (7:53-8:11) is missing from the earliest Greek manuscripts of John, including the two papyri from about AD 200 (P66 and P75) and the great fourth-century codices Sinaiticus and Vaticanus. It appears in Codex Bezae (fifth century) and in many later copies, some of which place it elsewhere, after John 7:36, after John 21:25 or in Luke after 21:38. The style of its Greek differs from John's. It is nevertheless old: the church fathers Ambrose and Augustine accept it, Jerome included it in the Latin Vulgate, and Papias, as reported by Eusebius, may refer to a similar story. Most critical scholars hold that it was not written by John but is likely an authentic memory of Jesus preserved in the early church. Some defenders of the Byzantine text-type, and the churches that have long read it, hold that it belongs in John. Modern translations usually bracket it or note it. The class treats it as ancient and instructive, and does not rest any claim about John's argument on it.

The rest of the chapter belongs to the part of the Gospel that scholars call the Book of Signs, where claims about Jesus' identity are tested in debate.

Chapter 8 is a sequence of debates in the temple, and like a debate it moves by challenge and reply. Each time the opponents misunderstand, Jesus presses the claim harder, until the final words bring the argument to a point and the stones. Readers should follow the thread of the single question that runs through every section: who is Jesus, and where is he from?

The interpretive caution concerns the phrase 'the Jews', which appears about seventy times in John. Jesus, his disciples and the earliest believers were all Jews. In this chapter the phrase names the particular opponents who have come to accept, reject and then try to kill him (8:31, 37, 59). John is writing a Jewish story of a Jewish Messiah, and he distinguishes some who believed from those who plotted. The history of using this chapter against the Jewish people is a misreading of John, and responsible interpreters on every side say so. Verse 44, which says that they belong to their father the devil, is spoken to those who seek to kill Jesus, and not to a nation.

The chapter's 'I am' sayings need care. In Greek, ego eimi can mean simply 'it is I'. In 8:24, 28 and 58 it stands without a predicate, and the context shows it carries more. The Greek Old Testament uses the same words for the LORD's self-naming in Isaiah 43:10 and 41:4 (and in Exodus 3:14 in a related form). The class follows the widely held reading that John wants his readers to hear that echo.

Chapter 7:53–8:11

Jesus teaches in the temple at dawn, and the scribes and Pharisees bring a woman caught in adultery, set her in the middle, and cite the law of Moses that such a woman is to be stoned (Leviticus 20:10; Deuteronomy 22:22-24). The test is a trap: if he says to stop, he sets himself against Moses; if he says to stone her, he sets himself against Rome, which reserved capital punishment (compare John 18:31). They also bring only the woman, though the law names both parties. Jesus stoops and writes on the ground. The text does not say what he wrote, and conjectures are only guesses. When they press him, he says that the one among them without sin should be the first to throw a stone. The law required witnesses to cast the first stones (Deuteronomy 17:7), so the answer holds them to their own testimony. One by one, beginning with the eldest, they leave. Jesus tells the woman that he does not condemn her either, and tells her to go and sin no more. He neither denies the sin nor sets aside the law; he refuses to be made the instrument of a trial that its accusers cannot sustain.

Verses 12–20

'I am the light of the world,' Jesus says; whoever follows him will not walk in darkness but will have the light of life. The Pharisees object that he testifies about himself, so his testimony is not valid. He replies that it is valid, because he knows where he came from and where he is going, and because he is not alone: the Father who sent him testifies with him, satisfying the rule of two witnesses (Deuteronomy 19:15). They ask where his Father is, and he says they know neither him nor the Father. John adds that no one arrested him, because his hour had not yet come.

Verses 21–30

He says he is going away, and they will seek him and die in their sin; where he goes they cannot come. They wonder if he will kill himself. He says they are from below and he is from above; unless they believe that he is who he says, 'I am', they will die in their sins. He adds that when they lift up the Son of Man, they will know that he is the one he claims to be (8:28). The 'lifting up' is the cross, as John says explicitly later (12:32-33), and it echoes the bronze serpent lifted up in the wilderness (3:14; Numbers 21:8-9). As he spoke, many believed in him.

Verses 31–47

To the Jews who had believed him, Jesus says that if they continue in his word they are truly his disciples; they will know the truth, and the truth will set them free. They protest that they are Abraham's descendants and have never been slaves to anyone. Their claim cannot be about history, since Israel had been enslaved in Egypt and Babylon and was under Rome, so the claim is more likely about freedom of spirit and standing before God. Jesus replies that everyone who sins is a slave to sin; a slave does not stay in the house forever, but a son does, and if the Son sets them free they will be free indeed. He grants that they are Abraham's descendants, yet they seek to kill him. Abraham did not do such things. If God were their Father they would love him. Instead they do the works of their father, and he calls this father the devil, a murderer from the beginning and a liar. The charge is moral and not racial: descent is shown by deeds, as John the Baptist had said (Matthew 3:9).

Verses 48–59

They say he is a Samaritan and has a demon. He answers that he honors his Father and does not seek his own glory, and that whoever keeps his word will never see death. They retort that Abraham and the prophets died; is he greater than Abraham? He says Abraham rejoiced to see his day, and he saw it and was glad. They ask how he, not yet fifty, has seen Abraham. Then comes the sentence on which the chapter turns: 'Before Abraham was born, I am!' The verb contrasts Abraham's coming into being with Jesus' simple existence. They pick up stones, the penalty for blasphemy (Leviticus 24:16), and Jesus hides himself and goes out of the temple.

Chapter 8 joins the doctrines of sin, freedom and the identity of the Son. The Bible teaches that sin is more than individual acts: it enslaves (Romans 6:16-20; 2 Peter 2:19), and the one who frees must come from outside. The Son, who belongs to the house, can set the slave free, because the son belongs to the house and the slave does not (8:35-36). This is the New Testament form of the exodus hope.

The chapter's argument about Abraham joins a theme that runs through Scripture. The promise was to Abraham's offspring, but not every physical descendant shares in it (Romans 9:6-8). Paul says that those of faith are the true sons of Abraham (Galatians 3:7, 29), and Jesus makes the same point here: descent is displayed in obedience. The claim that Abraham saw Jesus' day agrees with Hebrews 11:13 and with Jewish traditions that Abraham received visions of the future, though John does not say when this happened.

The claim at the chapter's end, 'before Abraham was born, I am', attributes to Jesus a kind of existence that is not bounded by time. This is the verse that the church fathers used against those who denied the Son's eternity, and it stands alongside John 1:1 and 17:5.

This chapter is direct revelation of Christ, with Old Testament threads running through it. The 'I am' of 8:58 is most naturally heard as an echo of God's name in Exodus 3:14 and of the repeated 'I am he' of Isaiah 41:4, 43:10 and 46:4 in the Greek Old Testament. The crowd's attempt to stone him shows they took it as a claim to be God (compare 10:33). It is not called a quotation, since John does not cite these passages, but the response of the hearers confirms the reading.

His words about being lifted up (8:28) point ahead to the cross, as John makes explicit in 12:32-33, and recall the bronze serpent of Numbers 21:8-9 (John 3:14). The claim that Abraham saw his day (8:56) presents him as the one to whom the promises to Abraham pointed, and Galatians 3:16 reads the promised offspring as Christ. The light claim fulfils the hope of Isaiah 42:6 and 49:6 that God's servant would be a light to the nations, and Simeon's words in Luke 2:32 say the same of the child.

In the story of the woman, Jesus appears as the one with authority to forgive, which in the Gospels belongs to God alone (Mark 2:7), and who yet does not abolish the law. The Gospel does not explain this tension here; it records both his grace and his demand.