"But although He had done so many signs before them, they did not believe in Him, that the word of Isaiah the prophet might be fulfilled, which he spoke: 'Lord, who has believed our report? And to whom has the arm of the LORD been revealed?' Therefore they could not believe, because Isaiah said again: 'He has blinded their eyes and hardened their hearts, lest they should see with their eyes, lest they should understand with their hearts and turn so that I should heal them.' These things Isaiah said when he saw His glory and spoke of Him."
Jesus had done so many miracles for them to witness, but they still did not believe. This is the tragedy of this book--unbelief. Jesus did not fail to convince His audience of who He was because His message failed or because His miracles were not convincing, the people wavered and fell into unbelief because of their hard-hearts.
Let it be remembered that one of Jesus' signs even included raising Lazarus from the dead. What kind of people would exhibit unbelief after witnessing a resurrection? The same kind of person that today would deny the essentiality of baptism despite the plain declarations of Mark 16:16, Acts 2:38, Acts 22:16, etc. When a person is determined not to "see," they won't--even if one is raised from the dead (cf. Luke 16:31)! Such a one is blind to the truth because he doesn't want to hear it, and no amount of evidence can persuade him.
John then quotes from Isaiah 53:1 - "Who has believed our report?" Isaiah had predicted that very few people would believe regarding the coming of the Messiah, and here is the fulfillment of such. "To whom has the arm of the Lord been revealed?" - This is merely another way of saying that the revelation of the Father through the Son had not penetrated the stubborn hearts of the unbelieving Jews.
"He has blinded their eyes and hardened their hearts, lest they should see with their eyes, lest they should understand with their hearts and turn, so that I should heal them" (Isa. 6:9,10). In this passage Isaiah is apparently commanded to harden the hearts of the people. If read superficially, it might seem that God desired to harden their hearts. But, certainly this cannot be true or they could not have been held accountable for their disbelief. Additionally, why would Jesus have exhorted them to believe in John 12:36 if such were not even possible for them? The proper interpretation is that God commanded Isaiah to teach, even though the people, by hardening themselves against his teaching, would be made worse rather than better by it. Thus, the unbelievers of Jesus' day had much in common with the Israelites of Isaiah's day. However, those with honest hearts who hungered for righteousness would certainly find what they were looking for (i.e., truth).
When one connects this context with Isaiah 6:1, it appears that the prophet saw the glory which Christ enjoyed in heaven (most likely in His pre-incarnate state). This vision inspired Isaiah to write what he did over 700 years before Jesus was born of the virgin Mary.
We will continue studying this passage in our next lesson.