I've been teaching an introductory philosophy course this semester with a new text for my God unit, Thinking About God by Greg Ganssle. It's designed to be usable for high school or introductory college/university courses, and it's just about the lowest level of detail that I would want to use for this course. I'm supplementing it some with other readings also, but it's nice to spend a lot of time just in one book after using lots of scattered readings in past versions of the course.
One thing that I found really interesting was in the section on the logical problem of evil. The logical problem of evil presents three traditional attributes of God (omnipotence, omniscience, and perfect goodness) and then seeks to derive a contradiction if you admit to the existence of evil (which pretty much all traditional theists will do, and thus it's a problem even if the person presenting the problem doesn't happen to believe in evil, because the theist does, and it's supposed to be a contradiction for theism). Now it so happens that hardly any philosopher today accepts the logical problem of evil as a good argument, for several reasons, but in the process of explaining why Ganssle hits on an interesting issue that I hadn't thought of before. One way some people have resisted theists' attempts to respond to the problem of evil might actually help the theist in surprising ways.
Responses to the logical problem of evil can involve explaining why a perfectly good, omniscient, omnipotent being would allow evil. For instance, free will is given as something important enough that God would want it, even if it means a fair amount of evil would be allowed. One kind of response to that (not taken seriously by most philosophers) is that if God is omnipotent then God should be able to give free will and also guarantee that people will freely do no evil. The standard response is that libertarian free will is incompatible with God guaranteeing what people will do, and God can't perform a contradiction, since contradictions are impossible. So God can't both give free will and guarantee what people will do, since guaranteeing what people will do violates free will. That would amount to performing a contradiction.
But isn't God omnipotent? Doesn't that mean God can do anything? The traditional answer is no. Rene Descartes is an extremely rare exception to the overwhelming consensus among theists that God cannot perform contradictions, because there is no such thing to be performed. Maybe you can define something called superomnipotence and then say that superomnipotent beings would be able to grant free will and then guarantee what people will do, but that's not the sort of thing theists hold to, because God is merely omnipotent. In fact, nothing could be superomnipotent anyway, and claiming that God is superomnipotent would already be claiming and impossibility.
What I found really interesting in Ganssle's discussion of this is that he thinks the superomnipotence objection to the problem of evil actually counts in the theist's behavior. What if the theist were to concede that God is superomnipotent? You might then think that God doesn't have a good reason for allowing evil anymore, since God could perform the contradiction to guarantee people's choices while maintaining their libertarian free will. But not so fast. Does God need a reason to allow evil if God is superomnipotent? Superomnipotence means God can perform contradictions. That means God can allow evil even if evil contradicts God's goodness, omnipotence, and omniscience. If you're going to allow contradictions with a superomnipotent being, then why is it at all problematic that God and evil contradict each other? This objection seems to fall flat if you allow God to be superomnipotent.
I had never considered that point before, and while I think Ganssle is right I do want to say one further thing. Once you allow contradictions, all logic goes out the window. Contradictions logically entail that every statement is true. So it's not going to be surprising if it turns out that the theist is not threatened anymore by the problem of evil, since every statement turns out to be true, including that one. But it's also going to be true that God is unjust and evil, since that's also going to be a statement, and every statement follows from contradictions. Once you allow contradictions you can prove that God doesn't exist just as much as you can prove that God is vindicated in allowing evil. In the end, I don't know if Ganssle's point establishes very much, since any statement follows as true once you allow contradictions. I do think it was an interesting observation, however. There's a reason hardly any philosopher has endorsed superomnipotence as a plausible interpretation of omnipotence. It's completely ridiculous to suppose that theists have ever meant that God can do something that makes God both exist and not exist, so omnipotence could never have meant that.