Basta

Make the heart of this people dull, and their ears heavy, and blind their eyes; lest they see with their eyes, and hear with their ears, and understand with their hearts, and turn and be healed.” Isaiah 6:10

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 12:20

The Calvinist passages ... “It’s not really my fault because God is the One who hardened my heart, so it’s His fault, just like old Pharaoh ... He was just being used by God to make a point.” 

It is true.  Our hearts are hard.  But He is not to blame, unless it is the blame of an overindulgent parent who will stop at nothing to bring us to Himself.  It is the hard heartedness of the older brother to whom the Father said, “Everything I have is yours, and always has been.” This is a repetition of “I have withheld nothing from you.”  After having prepared a beautiful vineyard and entrusting it to workers, The Landlord sends the messengers to collect His due, His fruit.  Articulate, passionate messengers.  Nothing.  Again and again, and nothing.  So He sends His Son who once again speaks truth, performs signs and wonders and humbling Himself to even death on a cross.  Nothing.  

The “dull” and “heavy” words of Isaiah are the sorts of words that are used to describe someone who has just finished a huge meal and does not even have the energy to push back from the table.  Eyes are glazed, and the heart is “fat,” and satiated.  Full of ourselves is the problem.  We need no Savior, we are enough.  We are bright, hardworking, have our system in place.  Who is this Landlord shaking the boat? 

The verb tense in John shifted to the imperfect. Here the imperfect is used with a negative, suggesting they were not about to believe because the intentionality was nonexistent. The idea is that they don't believe and are not in the mood or habit of believing, i.e., they had no intention of believing Him.

And Isaiah asks, “How long, O LORD?”  How long will these hearts be hard?  Until we come to the end of ourselves.  

Until the tree is chopped down.  And burned.  And then, and only then, For there is hope for a tree, if it be cut down, that it will sprout again, and that its shoots will not cease (Job 14:7)

And even though we have squandered all that He entrusted to us, He is still our mother, longing to gather her chicks under her wing, He is still our father, pacing back and forth on the road, looking for the repentant heart on the distant horizon.  

How then will they call on Him in whom they have not believed? How will they believe in Him whom they have not heard? And how will they hear without a preacher?

And I heard the voice of the Lord saying, “Whom shall I send, and who will go for Us?” Then I said, “Here I am! Send me.”