He had a vision of himself as a new kind of Christ as a man who carries within himself all the seeds of a new order of things. He was the new messiah of the battlefields saying to people as I am so shall you be. For he had seen the future he had tasted it and now he was living it.
This passage appears in the final chapter of Johnny Got His Gun, after Joe realizes that the hospital staff will never let him out to be seen by others, nor will they even let him continue to be conscious and communicative. Joe's vision of the future is an apocalyptic one of unending war. He realizes from the lack of human compassion that the hospital staff has shown him that there will not be enough human compassion in the future to forestall further warfare. Instead, the technology of modern war will take over.