Why is the only other explanation an experiment? Put that in formal logic. You don't have any argument. How do you know there is no other explanation. What if suffering was useful to God or permitted people to have free will? What if God made people intentionally frail so they would not challenge God's power in some other way?
Put in formal logic exactly how it follows from God's omniscience that God is required to give people a world without pain or suffering. Why should God even accept the categories of temporary human suffering as having any significant value?
Put in formal logic exactly how it follows from God's omniscience that God is required to give people a world without pain or suffering. Why should God even accept the categories of temporary human suffering as having any significant value?