The trial of Jesus plays a central and extended role in the book of John, with some seeing the entire book as a courtroom scene in which various witnesses are called in a trial of cosmic proportions in which God and humankind take turns in the dock. Besides the ambiguity as to who is acting as judge at his trial (does Pilate or Jesus sit in the seat of judgment in 19:13, see here), John uses trial language throughout his Gospel, and pictures John the Baptist and the writer (himself), or beloved disciple, as witnesses (1:6-8,15; 19:35; 21:24). The Gospel is framed as a legal proceeding, and John references and echoes the trial scene in Isaiah, in which God is the accused and the nations are arrayed against him as witnesses of the prosecution. God declares, let “All the nations gather together and the peoples assemble. Let them bring in their witnesses to prove they were right, so that others may hear and say, ‘It is true’” (Is. 43:9). At the same time, God brings forth Israel, and his key witness “my servant whom I have chosen” (Is. 43:10).
The chief thing to be proven in Isaiah is the identity of God as opposed to the gods of the nations: “so that you may know and believe me and understand that I am he. Before me no god was formed, nor will there be one after me” (43:10). As witness, Israel was to “know” and “believe” and witness to YHWH’s being “I Am.” Jesus’ calls for this same belief (πιστεύσητε—8:24) and knowledge (γνώσεσθε—8:28) as applying to himself, but he explains this will come about only when the judgment is passed and “you lift up the Son of Man.” Only then will you “know that I am He” (8:28). The language is precisely that of the Septuagint in Isaiah. The reference is not lost upon his listeners, as they would immediately execute judgment by stoning Jesus (8:58).
His betrayal, arrest, and death, would seem to be the point when they would presume he is not the “I am” but Jesus predicts the opposite. “From now on I am telling you before it comes to pass, so that when it does occur, you may believe that I am He” (13:19). This unmistakable recognition occurs on the night of his betrayal. When Jesus inquires of the soldiers whom they seek, and they say “Jesus the Nazarene,” he self-identifies in a way that bowls them over. “He said to them, ‘I am He.’ And Judas also, who was betraying Him, was standing with them. So when He said to them, ‘I am He,’ they drew back and fell to the ground” (18:5–6). The claim and recognition that this is the “I am He” of Isaiah is apparently self-evident, and like any theophany, overwhelming.
The claim, “I am He,” in Isaiah and the significance worked out in John has pertinence to all involved, as “apart from me there is no savior” (v. 11). There is only one who has “revealed and saved and proclaimed – I, and not some foreign god among you” (v. 12). Though they have wearied God with their sins and have not shown any gratitude for his mercy (Is. 43:24) still, “I, even I, am the one who wipes out your transgressions for My own sake, And I will not remember your sins (Is. 43:25).
The decision being handed down in these tandem trials is about the nature of reality and truth, the order of power, and the role of life and death, but ultimately it is about salvation. In both John and Isiah, this “judgment” is salvific. In Isaiah, though there are a series of harsh accusations, the beginning and end of the matter is to offer assurance. “‘Comfort, O comfort My people,’ says your God. ‘Speak kindly to Jerusalem; And call out to her, that her warfare has ended, That her iniquity has been removed, That she has received of the LORD’S hand Double for all her sins’” (Is 40:1–2). Through Israel, the same invitation is extended to all the nations: “Turn to Me and be saved, all the ends of the earth; For I am God, and there is no other. I have sworn by Myself, The word has gone forth from My mouth in righteousness And will not turn back, That to Me every knee will bow, every tongue will swear allegiance” (Is 45:22–23).
In John, Jesus gives the same assurance, though it too is mixed with various harsh condemnations. He describes his purpose as one of judgment, “For judgment I came into this world, so that those who do not see may see, and that those who see may become blind” (John 9:39). This judging works its effect in delivering from darkness, casting out the prince of this world and in exposing the lie undergirding this enslaving darkness. There is ultimate trust in the law of the cosmic order (“they have loved darkness” 3:19), an implicit trust in the power of death, and a first-order trust in the law of Moses (5:46), and on this basis a rejection and presumed judgment of Jesus is rendered. It is this false judgment that becomes God’s judgment and means of universal salvation (12:32).
Israel is supposed to be God’s witnesses “that I am God,” but as in Isaiah, so in the trial of Jesus, Israel does not prove trustworthy. Those who proclaim “we have no King but Caesar” (John 19:15) are those who formerly sided with the nations against God, and who stand accused and condemned: “Put Me in remembrance, let us argue our case together; State your cause, that you may be proved right. Your first forefather sinned, And your spokesmen have transgressed against Me. So I will pollute the princes of the sanctuary, And I will consign Jacob to the ban and Israel to revilement” (Is 43:26–28). Or as Jesus states it, “All who came before Me are thieves and robbers, but the sheep did not hear them” (10:8). “The thief comes only to steal and kill and destroy” (10:10). “He who is a hired hand, and not a shepherd, who is not the owner of the sheep, sees the wolf coming, and leaves the sheep and flees, and the wolf snatches them and scatters them” (10:12). “You are of your father the devil, and you want to do the desires of your father. He was a murderer from the beginning, and does not stand in the truth because there is no truth in him. Whenever he speaks a lie, he speaks from his own nature, for he is a liar and the father of lies” (8:44).
The characteristics of the truth and judgments of the cosmic order, which Jesus challenges, is that it is flesh bound, earth bound, or in the language of Charles Taylor, reliant on an immanent frame. According to Jesus, there is a regime of truth whose judgments are based on appearances (7:24), on the flesh (8:15), on what is below and without reference to a transcendent order (3:31; 6:33, 62; 8:23). Jesus counters this system of truth and judgment with the claim that he speaks for God (8:15-16) with a word which transcends the world and does not rely simply on human standards of judgment (e.g., 8:15, 23; 12:31; 18:36). In cosmic terms, this is like light against darkness, life against death, or God against humanity. “He who comes from above is above all, he who is of the earth is from the earth and speaks of the earth. He who comes from heaven is above all. What He has seen and heard, of that He testifies; and no one receives His testimony” (3:31–32). It is not an intrinsic problem with the law, but with the orientation that misses the transcendent referent of the law (5:46). The exposure of this lie and the revealing of the truth occurs throughout the life of Christ but comes to a culminating point at the trial and in the judgment of the cross.
The two regimes of truth, two modes of power, or two cosmic orders built on life or death, respectively, come into clear conflict and a judgment is rendered in the trial and its aftermath. However, as in Isaiah, the point of Jesus confrontation with the power of darkness and death is not simply judgment and condemnation but life: “I came that they may have life, and have it abundantly” (10:10). “For just as the Father raises the dead and gives them life, even so the Son also gives life to whom He wishes” (5:21).
As Isaiah describes it, in the clearest pointers to Jesus’ trial: “I gave My back to those who strike Me, And My cheeks to those who pluck out the beard; I did not cover My face from humiliation and spitting. For the Lord GOD helps Me, Therefore, I am not disgraced; Therefore, I have set My face like flint, And I know that I will not be ashamed” (Is 50:6–7). Trust in God in the face of death characterizes the Servant and describes Jesus confident march into Jerusalem and taking up of the cross. Those who condemned him presumed they had destroyed him and sealed him up in death: “By oppression and judgment He was taken away; And as for His generation, who considered That He was cut off out of the land of the living” (Is. 53:8). God’s judgment intervenes so as to set aside every human judgment: “Behold, My servant will prosper, He will be high and lifted up and greatly exalted” (Is. 52:13). God in Christ receives condemnation, but in the midst of this death his divine glory and life shine forth (lxx 52:14—ἡ δόξα . . . ἀπὸ τῶν ἀνθρώπων).
Jesus is the agent of God’s judgment, his claim upon the world. As Andrew Lincoln describes it, “that claim is now depicted in terms of God’s salvific judgment, which, through Jesus as its unique agent, inaugurates ‘life’ or ‘eternal life.’” All then are called before the judgment of the word of Christ: “He who rejects Me and does not receive My sayings, has one who judges him; the word I spoke is what will judge him at the last day” (12:48). The call is to believe and know that “I am” as he has overcome death; he is life and the source of eternal life (6:53-54). “I know that His commandment is eternal life; therefore the things I speak, I speak just as the Father has told Me” (Jn 12:50). “It is the Spirit who gives life; the flesh profits nothing; the words that I have spoken to you are spirit and are life” (6:63). This is judgment, that the light has broken into the darkness and all are called to the light (3:19).
 Andrew T. Lincoln, Truth on Trial: The Lawsuit Motif in the Fourth Gospel (Grand Rapids: Baker Academic, 2000). Lincoln has also updated his work in the article “A Life of Jesus as Testimony: The Divine Courtroom and the Gospel of John” available online at https://www.academia.edu/16852459/A_Life_of_Jesus_as_Testimony_The_Divine_Courtroom_in_the_Gospel_of_John
 According to Lincoln he uses “witness” or “testimony” (μαρτυρία occurring 14 times), the verb “to testify” (μαρτυρεῖν occurring thirty three times), judge (κρίνειν is employed nineteen times), or the legal or forensic notion of “truth” (ἀληθεία occurs twenty five times) or “true” (ἀληθής occurs some 14 times) or “trustworthy” (ἀληθινός occurs nine times). See the Lincoln article, Ibid.