Pardon me if I use this as a hook to explain something.
The problem of evil is an attempt, using logic, to say that a certain version of "God" cannot exist. It relies on certain premises.
God is omniscient
God is omnipotent
God is omnibenevolent
There are other premises that are not directly stated.
God can be judged by human standards (not so unreasonable as it might appear, as these attributes are claimed for God by humans).
These three attributes can be used with common meanings.
Evil exists.
So if you want to address the apparent paradox, saying that the premises don't apply or that we can't know God or other ways to dismiss the whole thing may be reasonable are not playing the game according to the rules. Of course, if you say that God isn't benevolent, powerful or whatever that does avoid the paradox, but you haven't solved anything because all you have done is change the premises, which will of course lead to a different conclusion.
God can't do all things, a lot of things are by just their nature impossible. He can do all possible things. The framework of possible worlds he creates is in fact constrained in that not everything we assert is possible is possible.
The non-suffering forced world could've been created or he could've made things that it would be very easy to obey God and very difficult to disobey to the extent near impossible.
For example, if he made Adam (a) into a luminous light fire being with more brightness and powers then all Angels, and his form was much higher, then Iblis would not disobey. But Angels (a) would not be tried with respect to their pride and they would be in a way worshiping God vainly.
And if he made a lesson of Satan, then everyone would never disobey purely out of fear of similar destruction right away.
However, the trial was made easy but not too easy. It was unexpected Iblis disobey nor Adam disobey. And so that is the next thing I don't agree with, God knows all possible things, but unset future cannot be known before it happens.
God has back up plans on top of back up plans. We in one of the last resort type plans.
He has been trying to correct and eliminate evil, given the constraints.
One of these constraints is that when he sends with miracles, if the first generations reject them, it's made difficult for later generations to narrate them and be trusted, and they face oppression severely. When miracles are denied by first generations after a founding Messenger it leads to prevention for later generations to see them unfortunately but God does it out of his grace. If people feared with respect to God and his miracles and signs, then he would continue to send them.
Now that the world is globalized, the rejecting of miracles would lead to a bigger catastrophe. Followers of Imam (a) also should not be like previous awaiting people in that when the savior from oppressors comes, they turn ungrateful after being saved (many of them, not all), and associate with God and denied his favors and begin to trouble the Messengers, Prophets, and Guides.
The Mahdi being the last test with Jesus returning and others like Elijah returning, the consequences on a world scale would be more severe. Therefore God is giving us time to set it up that more people are saved and fewer people condemned. But if the oppression becomes too severe and oppressors will get their way, it's upon God then to deliver the believers. So if forced to, God will do what he warned about and what he wanted us to avoid which is destruction of much of the world in terms of cities destroyed or punished severely.