Hello, I am a Catholic, I come in peace simply seeking understand Protestant thought a bit more from Protestants themselves.
Welcome! I hope you find some good answers here. Though as you have already seen you may have to look past some people here as any other forum. People are people and some have not overcome their nature of the flesh yet.
This is what I understand of Protestant anthropology and soteriology, at least according to the primary reformers i.e. Luther and Calvin. Please let me know if I am correct:
The original sin of Adam and Eve destroyed the goodness of man's nature and thereby destroyed the ability of his reason to know God or supernatural things, and also destroyed the freedom of his will thereby rendering him incapable of free moral actions.
You are close. I've never heard it said quite like that before though. I believe that when Adam sinned it caused us all to be dead in sin. Adam didn't physically die when he sinned. Instead he die spiritually and so we are dead spiritually.
Rom 5:12 Wherefore, as by one man sin entered into the world, and death by sin; and so death passed upon all men, for that all have sinned:
Because of man's total depravity of mind/will he is unable to participate in any way in his salvation and thus salvation is a matter of grace alone.
This is correct. Because man is dead in sin he can not choose the things of God. A dead man can not choose to get up and walk. A dead man can not hear. Something has to happen in order to change the nature of a dead man first. the event where Jesus brought Lazarus back to life was an example of this. Lazarus was dead, a corps. He could not hear, nor get up and walk on his own accord. Something had to happen first to make him able. God's grace is what makes us able to choose to believe and fallow Christ.
Now the consequence of this which Luther never seems to deny and Calvin affirms outright is that because salvation is by grace ALONE then the difference between those who are saved and those who are damned depends not on human responsibility but on God, hence Calvin's doctrine of predestination.
My first question is, have I understood this correctly?
This is where many people have very different views. Some believe we still have free will, as others do not. I am one who does not believe we have free will before the Lord first does a work in us through grace. So you will get many, many responses concerning free will.
Secondly my question is this: How does such a theory avoid altering radically both God and man in such a way that God seems to be unavoidably monsterous for creating people who have absolutelly no chance of salvation, and man seems to no longer be a responsible moral agent since he can neither know the good nor does he have any power (even assisted by grace) to co-operate in doing good? If man does not even have the power to co-operate how can we speak of him as a responsible moral agent? And if God, as Calvin insists, is ultimately the only agent in human actions, how is it that man and not God is responsible for sin?
If someone can please help me to understand better I would appreciate it, thanks
This is probably why you are getting the types of answers you are getting. However I do understand why you have put it this way. I will post a few verses that helped me with this same question. Though I sometimes still stumble on this one myself at times.
Rom 9:13-24/KJV
13 As it is written, Jacob have I loved, but Esau have I hated.
14 What shall we say then? Is there unrighteousness with God? God forbid.
15 For he saith to Moses, I will have mercy on whom I will have mercy, and I will have compassion on whom I will have compassion.
16 So then it is not of him that willeth, nor of him that runneth, but of God that sheweth mercy.
17 For the scripture saith unto Pharaoh, Even for this same purpose have I raised thee up, that I might shew my power in thee, and that my name might be declared throughout all the earth.
18 Therefore hath he mercy on whom he will have mercy, and whom he will he hardeneth.
19 Thou wilt say then unto me, Why doth he yet find fault? For who hath resisted his will?
20 Nay but, O man, who art thou that repliest against God? Shall the thing formed say to him that formed it, Why hast thou made me thus?
21 Hath not the potter power over the clay, of the same lump to make one vessel unto honour, and another unto dishonour?
22 What if God, willing to shew his wrath, and to make his power known, endured with much longsuffering the vessels of wrath fitted to destruction:
23 And that he might make known the riches of his glory on the vessels of mercy, which he had afore prepared unto glory,
24 Even us, whom he hath called, not of the Jews only, but also of the Gentiles?
