The crowds in Jerusalem are confused about who Jesus is. No one seems to know who he is - is He the Mesiah or not? Jesus says we don't know him because we don't know his father.
He shouts that He is the giver of real life. When you are confused and in chaos He gives voice and sanity!
25 Some of the people of Jerusalem therefore said, “Is not this the man whom they seek to kill? 26 And here he is, speaking openly, and they say nothing to him! Can it be that the authorities really know that this is the Christ? 27 But we know where this man comes from, and when the Christ appears, no one will know where he comes from.” 28 So Jesus proclaimed, as he taught in the temple, “You know me, and you know where I come from? But I have not come of my own accord. He who sent me is true, and him you do not know. 29 I know him, for I come from him, and he sent me.” 30 So they were seeking to arrest him, but no one laid a hand on him, because his hour had not yet come. 31 Yet many of the people believed in him. They said, “When the Christ appears, will he do more signs than this man has done?”
32 The Pharisees heard the crowd muttering these things about him, and the chief priests and Pharisees sent officers to arrest him. 33 Jesus then said, “I will be with you a little longer, and then I am going to him who sent me. 34 You will seek me and you will not find me. Where I am you cannot come.” 35 The Jews said to one another, “Where does this man intend to go that we will not find him? Does he intend to go to the Dispersion among the Greeks and teach the Greeks? 36 What does he mean by saying, ‘You will seek me and you will not find me,’ and, ‘Where I am you cannot come’?”
37 On the last day of the feast, the great day, Jesus stood up and cried out, “If anyone thirsts, let him come to me and drink. 38 Whoever believes in me, as the Scripture has said, ‘Out of his heart will flow rivers of living water.’” 39 Now this he said about the Spirit, whom those who believed in him were to receive, for as yet the Spirit had not been given, because Jesus was not yet glorified.
40 When they heard these words, some of the people said, “This really is the Prophet.” 41 Others said, “This is the Christ.” But some said, “Is the Christ to come from Galilee? 42 Has not the Scripture said that the Christ comes from the offspring of David, and comes from Bethlehem, the village where David was?” 43 So there was a division among the people over him. 44 Some of them wanted to arrest him, but no one laid hands on him.
45 The officers then came to the chief priests and Pharisees, who said to them, “Why did you not bring him?” 46 The officers answered, “No one ever spoke like this man!” 47 The Pharisees answered them, “Have you also been deceived? 48 Have any of the authorities or the Pharisees believed in him? 49 But this crowd that does not know the law is accursed.” 50 Nicodemus, who had gone to him before, and who was one of them, said to them, 51 “Does our law judge a man without first giving him a hearing and learning what he does?” 52 They replied, “Are you from Galilee too? Search and see that no prophet arises from Galilee.” (ESV)