What does John chapter 8 mean?The first section of this chapter describes Jesus' encounter with opponents who have brought Him a woman guilty of sin. In this incident, Jesus demonstrates that these men are acting hypocritically: attempting to trick Jesus using the law, while they themselves are not completely following it! At the same time, Jesus shows that simply having power, such as the authority to execute a guilty sinner, does not make using it the best choice. Instead, Jesus demonstrates mercy and fully applies both the letter and intent of the law, as God intended: with "right judgment."
This story of the adulterous woman, however, is almost certainly not original to the gospel of John. Different manuscripts have these verses in different places, sometimes attached to the end of completely different New Testament works. This, along with other evidence, has led scholars to believe the story of the adulterous woman to be a true, accurate description of a real event, but not one intended to be read in this exact place. So, this story is something of a side-note, and not part of Jesus' actions during the Feast of Booths. Instead, the action which was interrupted after John 7:52 will resume in John 8:12.
As Jesus continues to teach at the Feast of Booths, He uses another analogy related to festival rituals. In this case, it is the burning of lamps, whose wicks were made from priestly garments. Jesus makes the second of His seven "I AM" statements highlighted in the gospel of John, declaring that He is "the light of the world." This incorporates Jewish ideals of truth and knowledge, as well as professing to be the one and only source of spiritual truth.
This sets off a debate between Jesus and His most vehement opponents: the religious leaders of Jerusalem and their followers. John collectively refers to this faction as "The Jews" in His writing. Their stance is based on genealogy: they are the descendants of Abraham, so they claim to be favored by God. Jesus, however, points out that spiritual relationships matter more than family lines. Since children act like their fathers, those who legitimately follow God should be obedient to His message, as Abraham was. But the men seeking to oppose Jesus act more like the devil: they deal in lies and murder (John 8:44; John 5:18). Therefore, these men don't actually know God. In fact, they don't want to know God, since the truth is something they can't bear to hear (John 8:43).
As the conversation continues, it will become more and more charged. Jesus' critics will resort to insults, including smearing His birth (John 8:41) and suggesting that He is insane (John 8:48). Jesus will respond by continuing to discuss Abraham, and suggesting that He has first-hand knowledge of Abraham's response to His own ministry (John 8:56). When the crowd misunderstands, Jesus explicitly claims to be God by declaring "before Abraham was, 'I am,'" using the same name God applied to Himself when speaking to Moses (John 8:58; Exodus 3:14). The reaction, as one would expect, was not only angry, but violent. Jesus' enemies once again try—unsuccessfully—to kill Him.