1. Some ask if we “place limits on God” when we say there are certain things He cannot do.
When we say “God can’t make a square circle” we aren’t limiting Him. We are simply stating that one of the things a circle is not is a square. Likewise, to say “God can’t make the past not to have happened” is defining the past as “that which has happened.” These aren’t limits on omnipotency, but are actually just definitions of the terms we are using.
In fact, I believe we aren’t saying that God can’t do these “things,” but rather, a square circle is not a “thing.” A circle, by definition, is not a square. Since it is created, it is not infinite. Being finite, we “de-fine” it. Part of being a human is not being a rock, not being a square root, and not being a tree. When we state what a human is, we understand by that very definition that it is NOT those other things. Apply this to a square circle. A contradiction of terms is not comparable to a limit on power.
2. A somewhat related and certainly interesting question that has been debated through the centuries by philosophers and theologians is this:
Did God create the best possible world, or could He have created one better? If he did not create the best, why not? And if He did, it seems very odd that we have so many evils, etc. It seems that God could have created a world with no possibility of evil, and only goodness…but would this have actually been better? For God “permits evil for a greater good;” but couldn’t God have made this “better good” without the evil, and would not that have been better?
These questions are related to the omnipotence, goodness, and freedom of God. I think they are interesting questions.
Briefly, my personal theory is this. “Freedom” is so important that God, if He created a “puppet” world where all was perfect by necessity, it would actually be not as good. Freedom is hard to quantify, but I believe that, somewhere in there, it is the factor that “influenced” (I dare not say determined) the type of world God would create.
Of course, freedom can be freedom for excellence, and not freedom of indifference (getting into moral theory now), but I still think the freedom question is [somehow] the answer.
Those are my brief thoughts…