Throughout our study of John 12, we have seen much Jewish unbelief regarding Jesus. Verses 1–8 record the objections of Judas to the honor Mary showed to our Lord when she anointed Him. In verses 9–11 and 19, we read that the Jewish religious leaders rejected Jesus. Finally, verses 34–36 testify that many Jews in Jerusalem during the last week of Jesus’ earthly ministry found it hard to believe in Him. They had difficulty understanding His teaching about the necessity of His death, and Jesus warned that they had to believe in Him before it was too late. He saw the people’s hearts and knew many of them were on the verge of rejecting Him.
In today’s passage, John gives a theological explanation for this hardness of heart. Turning first to Isaiah 53:1, John says the Jewish unbelief fulfills the question asked about the Suffering Servant. Isaiah saw that many would reject the Messiah, and the rejection of Jesus by many Jews is the fulfillment of that prophecy (John 12:36b–38).
Next, John looks to Isaiah 6:10, where God says He will harden many people to the truth of Isaiah’s message. As the Lord kept many people from believing Isaiah, so did He harden the hearts of many first-century Jews against Jesus (John 12:39–40). This may sound harsh or even “unfair,” but note that the biblical authors have no problem attributing an individual’s rejection of divine truth to the working of both the one who rejects it and to God Himself. As we see in the case of Pharaoh in the book of Exodus, God is not dealing with people who earnestly want to believe in Him when He hardens the hearts of men and women. Instead, He hands over to unbelief those who, because they are born in sin, have no desire to believe. He does not have to create fresh evil, as it were, in a sinner’s heart. Instead, in His judgment He gives fallen people what they want, and apart from divine grace, they want nothing to do with God and His glory. Augustine of Hippo comments that “God . . . blinds and hardens, simply by letting alone and withdrawing His aid: and God can do this by a judgment that is hidden, although not by one that is unrighteous.”
Finally, John 12:41 tells us that Isaiah prophesied as he did because he saw the glory of Christ. Since John quotes from Isaiah 6, where Isaiah’s vision of God is recorded, we likely have reference to a vision of the preincarnate Christ. When Isaiah saw God sitting on His throne high and lifted up (Isa. 6:1–7), he saw the Son of God.