Hello,
I definitely do not consider myself one to be of Luther or Calvin. However, I used to relate to others by saying that I was a blend of the two. After having received the Indwelling Spirit in the most profound and physically measurable way, I realized that to follow the ideas of simple "man" was foolish. I abandoned every teaching any human had ever given to me and began looking at the Word of God (alone). I only look at commentary but a handful of times per year . . . as in five or less. I used to own hardcover commentaries, dictionaries, the TSK, tons of recordings of John Macarthur, etc, yadda yadda. They're all gone. Once I abandoned the teachings of "men" and began reading the Bible literally word by word (attempting to understand everything I was reading and how it all related in a timeline, chronological order), I saw a completely different Bible. My view of the Bible was no longer based on what others told me I should see, but it was based on what God wanted me to see. And this is not to say that I was without flaws. No way. In fact, each time that I discover that I am wrong about something, I break out in cold sweats. I am mortified to find that I have taught things that we wrong. For, having felt the Raw, Almighty Power of God, I rest in terror thinking that I have been teaching others something that is contrary to His Holy Word (and Plan).
So, no . . . I do not even recall what Luther or Calvin taught. All of that is jibber-jabber to me. I don't care about what others believe, but instead, I care about what [we] believe here at the forum. I turn to all of you before any person who has written a book. I'd rather ask questions and speak with all of you . . . first.
As for the hardening of hearts, I see two things going on. The actual hardening of the heart is done by God; this is something that is beyond our control. When another person hardens their heart, this is another way of saying that we become stubborn, as in the case of Pharaoh. No person can harden or unharden their hearts, for this would be the equivalent of the choice of being under the Curse of the Sinful Nature and deciding to no longer be under the Curse. No human has this ability to lift and apply said Curse of the Lord. But to become stubborn seems to be something of a different form. But hey . . . I'm not an expert on the matter.
When it comes to Pharaoh, I just accept what is said about him, which is that God used Pharaoh to demonstrate His Almighty Power through him . . . which includes the control over his thoughts and decisions regarding the Jews.
I could write more, but I've got some studying to do. Peace to you.