If this is true, then it is God's fault when a man goes to Hell because that man had no opportunity for salvation from birth.
Everyone on earth has exactly the same opportunity for salvation from birth.
It is not God's fault that men go to Hell. It is their own fault for being sinners.
God is not to be faulted for putting mankind under a curse. We are under a curse because of the sins of the head of mankind - the first Adam.
Likewise those who are made new creatures in the last Adam are not under the curse.
They are justified by faith just as the original Adam was "unjustified" by lack of faith. That, it seems to me, is altogether fitting.
What is necessary is a new creation according to the Word of God and according to Calvinist doctrine.
Do I like the fact that I was born under a curse and spiritually dead? No - not any more than you do probably.
But if that's the way of things according to the Word of God then that's the way it is.
I'm not going to second guess the way God decided to display His innate knowledge of good and evil in this age or the way He will do it in the ages to come.
Your problem is with the doctrine of original sin - not with Calvinists. Even you Papal authorities believe in and teach the doctrine of original sin.
I don't like things the way they are and if I had my way everyone under the curse of God would have been saved by the sacrifice of Christ once for all.
But that's not the way things work.
Natural men will not believe and be saved unless acted upon by God in a certain way in grace. That's simply what the Bible teaches.
If God chooses to so act in grace for one man and pass another by for whatever purpose He does that - the man He passes by is not less guilty of sin and worthy of Hell than he was before God passed him by.
The flesh profits nothing. What is necessary is a new creation.
Could it be that your understanding of Unconditional Election and Irresistible Grace is different than that of a true Five Points Calvinist?
For the purpose of our conversation - it's not enough different so that I can't defend the Calvinist doctrine of unconditional election and irresistible grace with you here.
But - yes - I would definitely nuance those doctrines much more than the way they are usually put forward by most 5-point Calvinists. The same is true for all of the so called 5 points of Calvinisms - limited atonement in particular.