The horrors of physical suffering correspond to the horrors of moral and spiritual outrage. Sometimes this means that people's suffering is directly correlated with their immorality and belittling of God. This will be the case, for example, with the eternal suffering of hell. It will correspond in perfectly just measure with the outrage of an individual's sin.
But often the correlation is indirect. Everyone suffers physically because of the outrage of Adam's sin, and because of God's subjecting all of creation to futility (Romans 8:20). But these sufferings do not all correspond to an individual's particular sins. All physical suffering corresponds to moral and spiritual outrage, but not all suffering corresponds directly to individual sins.
What is stunning and essential to see is that physical horrors correspond to spiritual horrors. God knows that we do not feel horrible about the spiritual horror of our sin. We take it lightly. But we get very angry and very agitated and very indignant about the horrors of our physical suffering. So God correlates the two in order to make plain to us how horrible sin is. Belittling God feels like a light thing to us. Being burned feels huge.
So hell will be physical, not just spiritual, even though the greatest outrages of life are not physical. The greatest outrages of life are spiritual—the demeaning of God by unbelief and indifference and rebellion is the greatest outrage in the universe. It may produce the holocaust or it may produce self-exalting philanthropy. But the magnitude of the moral horror in both cases is mainly Godward. Belittling God's infinite worth is the ultimate outrage.
Here is a picture of what I mean.
God says to the exiles in Babylon concerning the false prophets, Ahab and Zedekiah:
Because of them this curse shall be used by all the exiles from Judah in Babylon: "The Lord make you like Zedekiah and Ahab, whom the king of Babylon roasted in the fire," because they have done an outrageous thing in Israel, they have committed adultery with their neighbors' wives, and they have spoken in my name lying words that I did not command them. (Jeremiah 29:22-23).
I am shocked by the term "roasted." Why such a description? It actually happened, that's why. Nebuchadnezzar roasted them. And why did it happen? Why such an outrageous physical horror and why such an outrageous physical word used to describe it?
Because speaking false things about God and committing adultery does not feel outrageous to us. But roasting someone in the fire does. So God correlates the two so we would learn what is really outrageous in the world. Demeaning God and breaking covenants.
The physical suffering of this age is God's warning: This is how horrible and outrageous sin is. Flee it while there is time. Turn to Christ for forgiveness.
The physical suffering of eternity is God's judgment: This is how horrible and outrageous sin was. Now there is no fleeing. It is too late.