This is second one of Jesus’ great “I AMs.” The fact that Jesus says this after He forgives the adulterous woman shows the power of this statement. Jesus brought spiritual light into that woman’s life. She did not have to walk in spiritual darkness anymore. She could walk in the light of Jesus Christ.
It is not in the first copy of the book of John when he wrote it. Few doubt that the place where it finally was put was well chosen. Jesus proclaimed Himself the true light of the world. Jesus is the Light. Note http://ref.ly/Jn1.7-9 where John identifies Jesus as this special light. The woman and her accusers reveal the dark nature of sin than anything yet recorded in John’s Gospel. The purity and brightness of Jesus shine through abundantly. Jesus is the light of life. Note John 3, which reveals that men love darkness rather than light because their deeds are evil. This image is further developed in I John.
If you and I are to understand the full import of what Jesus is saying here, you and I must understand what Jesus was referring. This is particularly important because it is not what we would most naturally think. We may think of the sun. In Malachi, the Messiah is spoken of as the “sun of righteousness. There is healing in its wings. This is not a bad thing to do. It is not the image Jesus is using in this scripture.
These words were spoken shortly after the Feast of Tabernacles. This was held in the courtyard of the temple area. (Verse 20). The ceremonies that were a part of that feast were conducted.
The second ceremony of this feast was similar. On the first night of the feast, and probably succeeding nights also, after the sun had set, two great lamps were lighted in the courts of the temple. These were said to have cast their light over every quarter of the city. The lamps were meant to recall the pillar of cloud and fire that had accompanied the people in their wanderings in the wilderness. This light stood between the Israelites and the pursuing armies of the Egyptians. This was the night before the crossing of the Red Sea. It is believed that it was a clear reference to the ceremony of lighting the lamps and naturally, therefore, also to the miraculous cloud itself that Jesus refers to when He claims to be this world’s light.
This conclusion is supported in John 6, 7, and 8. In John 6, Jesus is the new manna sent down from heaven. In John 7, He is the water miraculously provided from the rock. In John 8, he is the cloud. Therefore, you and I must turn to the cloud itself and its functions in order to determine the full meaning of this saying in John’s Gospel. The cloud gave off light, and it symbolized God’s presence. Light would always suggest God’s presence. The cloud was so huge and so striking that this in itself would suggest a theophany.