“And He said, To you it has been given to know the mysteries of the kingdom of God, but to the rest in parables, that seeing they might not see, and hearing, they might not understand” (Luke 8:10).
“But though He had done so many miraculous signs before them, they did not believe into Him, so that the Word of Isaiah the prophet might be fulfilled, which he said, ‘Lord, who has believed our report? And the arm of the Lord, to whom was it revealed?’ Because of this they could not believe, because Isaiah said again, ‘He has blinded their eyes’ and ‘has hardened their heart,’ ‘that they might not see with the eyes’ and ‘understand with the heart,’ ‘and be converted,’ ‘and I should heal them.’ Isaiah said these things when he saw His glory, and spoke about Him” (John 12:37-41).
Now let us ask WHY certain people could not believe. Is it because they did not exercise alleged “free wills”?
Is it because they did not make the best use of any alleged “prevenient grace” or “common operations of the Spirit”? Not at all. WHY then could they not believe? Because God had blinded their eyes that they might not see, nor understand and be converted (i.e., saved). The verse (v. 41) ends with the statement that this blinding and hardening of certain people is a manifestation of the glory of Jesus Christ:
To those whom God has chosen and for whom Christ has died, this knowledge of the glory of God in the face of Jesus Christ, is shown in their hearts upon regeneration (2 Corinthians 4:6). But to those who have been chosen for damnation, those for whom Christ did NOT die, this glory of Jesus Christ does not dawn on them:
“But also if our gospel is being hidden, it has been hidden in those being lost, in whom the god of this age has blinded the thoughts of the unbelieving, so that the brightness of the gospel of the glory of Christ who is the image of God, should not dawn on them. For we do not proclaim ourselves, but Christ Jesus as Lord, and ourselves your slaves for the sake of Jesus. Because it is God who said, “Out of darkness Light shall shine,” who shone in our hearts to give the brightness of the knowledge of the glory of God in the face of Jesus Christ” (2 Corinthians 4:3-6).
No wonder the Roman Catholics deny Sola Scriptura with “unloving” verses like those in John 12:37-41. And no wonder many Protestants slide-on-over, by returning to Rome. No wonder many professing Christians even deny plenary inspiration. But hey, at least they are more honest than those who would affirm plenary inspiration, while denying the plain and clear teaching of the aforementioned “unloving” verses.