12 Again Jesus spoke to them, saying, “I am the light of the world. Whoever follows me will not walk in darkness, but will have the light of life.” 13 So the Pharisees said to him, “You are bearing witness about yourself; your testimony is not true.”
25 So they said to him, “Who are you?” Jesus said to them, “Just what I have been telling you from the beginning.John 8:12–13, 25
The judgment-witnesss-testimony themes first introduced in chapter 5 and dominating chapter 7 are sustained throughout chapter 8 as well. The first portion of which, divides into two scenes. In the first there is a movement from who to where (8:12–20). In the second there is a movement from where back to who (8:21–30). In each section they ask a question by which they seek to invalidate Jesus but which really masterfully serves to invalidate themselves.
In the first instance, they ask “Where is your father?” Indicating that they don’t know who has sent Jesus (7:28–29), they don’t know from whence He has come (8:14), they have judged before learning anything about Jesus (7:51). They have judged according to appearances (7:24). They have judged according to the flesh (8:15).
But it is the second question in the second portion that is really the most glorious. The first builds toward the second. Look back. Jesus has opened the “trial” with this opening statement as to who He is: “I am the light of the World.” They say this testimony is invalid. He is bearing witness to himself. But now, in this second round of arguments, here they are asking Jesus to do just that. “Who are you?” Just as He has been telling them from the beginning. He is the I Am.
“I am the Light of the World” (8:12; cf. Psalm 27:1).
“I told you that you would die in your sins, for unless you believe that I am
he you will die in your sins” (8:24; emphasis mine; the “he” is supplied by the translators).
“When you have lifted up the Son of Man, then you will know that I am
he, and that I do nothing on my own authority, but speak just as the Father taught me” (8:24; emphasis mine; the “he” is supplied by the translators).