“neither do they understand.” Why do the listeners not understand? Is it because they have covered their own ears and closed their hearts, as Matthew’s record portrays (Matthew 13:14-15), or because God has blinded their eyes and hardened their hearts as John’s words could be read to say (John 12:38-40)? The answer comes only when we put these two records together and understand them in light of the entirety of scripture’s teaching on this subject.
Why did the Lord speak to the crowds with parables? To this question Christ could have responded that he takes his own advice, by not throwing his pearls before the swine. God says, “Do not speak in the hearing of a fool, for he will despise the good sense of your words” (Prov. 23:9). Parables are designed so that the hearers must think, seek, and even ask to understand. By speaking to the crowds in this way, the Lord separates those who have a will to listen and be healed from those who foolishly reject his teachings.
All three synoptic gospels record the parable of the Sower in the context of the fulfillment of the prophecy of Isaiah (Matt. 13:10-18; Mark 4:2-12; Luke 8:9-11). John does not relate the Sower parable but speaks of the prophecy of Isaiah: John 12:35-42. It is interesting that the Sower is related in this context, for this parable deals with how one’s heart is prepared to receive the Good News. In the parable of the Sower there is no indication that God decides what kind of soil one’s heart is. Rather, it is the own person’s responsibility to determine the nature of his heart’s soil. This is where the quotation from Isaiah comes in. Jesus says in Matthew the prophecy “is fulfilled” (Mat. 13:14, present indicative), in that some of those listening had dull hearts and could barely hear, and further that they have chosen to close their eyes and ears lest they see, hear, understand, and turn. The Greek word for “lest,” mepote (#3379 μήποτε), is an indicator of negative purpose, showing they purposely intended to not see, hear, or understand. These Jews hardened their hearts against God.
John begins the record by pointing out even though Jesus had done so many signs before these people, they still did not believe in him (John 12:37). This “resulted in” another word of Isaiah being fulfilled regarding Israel’s unbelief: “Who has believed what he heard from us?” (John 12:38). The “resulted in” expression of this verse is a hina with a verb in the subjunctive result clause (see commentary on Matt. 2:15; “resulting in…what was spoken being fulfilled”). John says it was “for this reason,” “on account of this,” (Greek: dia touto) that these people could not believe (John 12:39). That is to say, because they rejected Jesus and refused to believe, “He has blinded their eyes and hardened their heart, lest they see with their eyes, and understand with their heart, and turn, and I would heal them” (John 12:40).
God is portrayed as doing the blinding and hardening in the passage in John. Yet we know from Matthew these people hardened their own hearts first by choosing not to believe. John tells us that it was because of this unbelief they were blinded. How are we to understand this blinding? It is not as though God actively hardens the hearts of those who close their eyes to the truth. Rather, he has allowed them to be blinded by setting in place a spiritual principal that while one is rejecting Jesus they are left in a state of spiritual blindness. It is the idiom of permission [See Graeser, Lynn, Schoenheit, Don’t Blame God, Ch. 4, and commentary on Romans 9:18]. Scripture teaches that in actuality, the Devil is the one who blinds these people: “In their case the god of this world has blinded the minds of the unbelievers, to keep them from seeing the light of the gospel of the glory of Christ” (2 Cor. 4:4); it is only when they turn to the Lord that the veil is taken away (2 Cor. 3:14-16). Unbelievers have dull hearts and ears that can barely hear, but whether they will turn to the Lord or decide to close their eyes is their free choice. If they turn to him, the veil is lifted off their hearts and they can see at last. But if they choose to reject Christ and close their eyes, as some did on this day, those people remain under Satan’s dominion of spiritual blindness. This is why Christ told these people, “The light is among you for a little while longer. Walk while you have the light, lest darkness overtake you… While you have the light, believe in the light, that you may become sons of light (John 12:35-36).
Once someone rejects the light they are “overtaken” by darkness and God allows them to stay in this state until they turn to the Lord and are healed—so that Christ may be the only means of spiritual enlightenment. Only in the sense of this permission can it be said that God blinds them and hardens their hearts. Thus we can get to the proper understanding of these passages only if we consider the whole of scripture. We must put the records together to understand the full picture, that people first choose to harden their own hearts and as a result are left by God in a state of spiritual blindness.
When this record occurs in Mark 4:12 and Luke 8:10 it comes in the form of two purpose-result clauses (see commentary on Matt. 2:15; “resulting in…what was spoken being fulfilled”), thus sandwiching the truth revealed in Matthew and John together into one perspective. They write that Christ’s teachings come in parables “so that” the people may see but not perceive, hear but not understand. The “so that” indicates the purpose and the result of the speaking in parables.