If Hell is eternal, God cannot be both omnipotent and benevolent
This is addressed to Christians who believe hell is eternal. This topic also assumes that eternal hell is a justified punishment and that free will exists.
Thesis: If God created the humans who will eventually end up in hell with the knowledge of their eventual fate, then he cannot be benevolent. This is because if he were truly benevolent, he would have avoided any course of action which would have lead anyone to experience eternal suffering.
A response to this that I anticipate is that God wants us to have free will, and if he only allows those who will end up in heaven to be born, he has rigged the game from the start, thus making free will virtually nonexistent.
My rebuttal to this is that it doesn't matter whether free will is robbed or not if the end result is that millions or, more likely, billions of people are going go inevitably end up suffering eternally. If God is benevolent and omnipotent, then he must choose the course of action that will minimize the amount of suffering, no matter the cost. If the rest of the population must have their free will forfeited in order to prevent the eternal suffering of billions, then so be it.
Here's an analogy: imagine your son or daughter is threatening to kill themself as a result of a hard breakup. Wouldn't you agree that it is your duty as a parent and a fellow human being to do everything in your power to stop them from making such an irrational decision, even if doing so robs them of their free will?