Skandelon said:
I would say hardening has to do with ones ability to hear, see, understand and repent. Calvinists teach men are born unable to do these things unless first regenerated, but the bible teaches differently. Consider this passage:
Acts 28:27 For this people's [Israel] heart has become calloused; they hardly hear with their ears, and they have closed their eyes. Otherwise they might see with their eyes, hear with their ears, understand with their hearts and turn, and I would heal them.' 28 "Therefore I want you to know that God's salvation has been sent to the Gentiles, and they will listen!"
With respect, you misunderstand the passage.
Acts 28:25-29 25 And when they did not agree with one another, they began leaving after Paul had spoken one parting word, "The Holy Spirit rightly spoke through Isaiah the prophet to your fathers, 26 saying, 'GO TO THIS PEOPLE AND SAY, "YOU WILL KEEP ON HEARING, BUT WILL NOT UNDERSTAND; AND YOU WILL KEEP ON SEEING, BUT WILL NOT PERCEIVE; 27 FOR THE HEART OF THIS PEOPLE HAS BECOME DULL, AND WITH THEIR EARS THEY SCARCELY HEAR, AND THEY HAVE CLOSED THEIR EYES; OTHERWISE THEY MIGHT SEE WITH THEIR EYES, AND HEAR WITH THEIR EARS, AND UNDERSTAND WITH THEIR HEART AND RETURN, AND I WOULD HEAL THEM."' 28 "Therefore let it be known to you that this salvation of God has been sent to the Gentiles; they will also listen." 29 When he had spoken these words, the Jews departed, having a great dispute among themselves. (NASB)
The issue here has absolutely nothing to do with the ability or inability to believe. Paul witnessed first hand the hardness in the heart of some of the Jews who listened to his reasoning. He rightly diagnosed their condition when he cited the prophet in verses 26 & 27. Paul is connecting these contemporary unbelieving Jews with the unbelieving Jews during the time of the prophet. Their hearts were hardened; they were unable to accept the truth because their hearts were hardened.
Now, a good question to ask is, "why were their hearts hardened?" Did they bear any responsibility? Certainly! The DoG does not, as some wrongly assume, relieve mankind from responsibility:
Acts 17:30 God is now declaring to men that all people everywhere should repent,
Man bears the responsibility for his own sin; whether in the free will schema or the DoG schema.
Since the passage in Acts 28 doesn't deal with the issue of ability/inability, we must look elsewhere in Scripture. Romans 9 is a perfect place.
Romans 9:14-20 14 What shall we say then? There is no injustice with God, is there? May it never be! 15 For He says to Moses, "I WILL HAVE MERCY ON WHOM I HAVE MERCY, AND I WILL HAVE COMPASSION ON WHOM I HAVE COMPASSION." 16 So then it does not depend on the man who wills or the man who runs, but on God who has mercy. 17 For the Scripture says to Pharaoh, "FOR THIS VERY PURPOSE I RAISED YOU UP, TO DEMONSTRATE MY POWER IN YOU, AND THAT MY NAME MIGHT BE PROCLAIMED THROUGHOUT THE WHOLE EARTH." 18 So then He has mercy on whom He desires, and He hardens whom He desires. 19 You will say to me then, "Why does He still find fault? For who resists His will?" 20 On the contrary, who are you, O man, who answers back to God? The thing molded will not say to the molder, "Why did you make me like this," will it?
There is precedent in Scripture to prove God does harden hearts. God does not harden the hearts of His children. On the contrary, He calls His sheep and His sheep hear His voice (John 10).
Skandelon said:
What about those who are hardened and later get saved? Like Israel who is later provoked to envy by the salvation of the gentiles and come to salvation? (ref Rom 11:14)
What about them? All of us came to Christ through a series of God ordained events. None of us are born saved. Ephesians 2 explains to us that even the Apostle was a son of disobedience before he was gloriously saved (Eph. 2:3). We are linear creatures that often times can't see past the tip of our nose. God is outside of space and time. He is the Alpha and Omega; seeing the past, present, and future before Him at all times. Is it possible that some of the unbelieving Jews in Acts 28 may have come to faith a later date? Sure. Does that exclude the possibility that, while in their hardened and unbelieving state, that they were unable to believe? No, it doesn't.