The prophet Isaiah received a hard word from God: "Go and tell this people: 'Be ever hearing, but never understanding; be ever seeing, but never perceiving.' Make the heart of this people calloused; make their ears dull and close their eyes. Otherwise they might see with their eyes, hear with their ears, understand with their hearts, and turn and be healed" (Isaiah 6:9-10). A tough word, an even tougher assignment.
Can it be true that God clouds the truth from certain people? Does God want to keep certain outsiders outside?
Unless you think this is merely an example of Old Testament cruelty, Jesus quoted the same words in the gospels of Matthew and Mark when he told the parable of the seed and the ground.
Isaiah was surrounded by false prophets preaching a false message. They were soft on sin and long on affirmation. They told people what they wanted to hear: "Everyone makes a mistake or two; don't worry about it; you're too good to worry about a misstep here or there." Isaiah cut across their 'feel good' message with sin-revealing truth and a call to serious repentance. Who wants to hear that kind of message?
So God clouded the truth from those who didn't want the truth. He affirmed the deliberately disobedient in their disobedience and the rebellious in their rebellion. Papa-God hid revelation from the people who despised revelation. He allowed anyone who chose to be outside of grace to stay outside of grace. He allowed outsiders to remain outside.
Jesus quoted this passage because he knew that most of the people who heard his call to repentance didn't believe they needed to repent. And Jesus also knew that most of them didn't believe Jesus to be who he says he is -- God's Son. They were indifferent both to the message of truth and the messenger who is Truth.
Therefore, God clouded the truth and kept them outside of grace.
Is that fair?
It's want they wanted. It was the destiny of their own making. And it's a warning to us all.