Does the author mean to say that a six week old baby who died during the Periclean age of Athens is roasting and popping in Hell?
My answer to you is that God is righteous. We will not know what He does with the souls who died before they had a chance to decide (including millions of the unborn) but, whatever it is, it will be fitting with God’s holiness and righteousness.
I didn’t have Christianity truly presented to me until I was 18 (although I had been given a pocket New Testament in the fourth grade which meant nothing to me although I tried to read it and did not understand). Would I be condemned if I had died before then? I don’t know. All I know is that God is righteous and He has this all figured out according to His justice and mercy.