The following was written by Alex McFarland. My comments at the end.
“A common encounter I’ve had when speaking at a university or when answering questions in an open forum is for someone to smugly ask, “Can God make a rock so big that He can’t lift it?” The challenge inherent in this question is whether there’s something God cannot do. Nonbelievers enjoy asking this question because either way we respond, we submit that there is, in fact, something God cannot accomplish. Either we answer that God can make a big rock He cannot lift or that God cannot make a rock big enough that He can’t lift it. The “big rock” question is a seemingly insolvable conundrum. However, this famous question in no way puts God in some kind of cosmic checkmate. In fact, this question in no way proves there’s something God cannot do. It is simply a meaningless question that implodes on itself.
Essentially, the questioner is asking, “Is there any way that the God who can make all things can make a rock so big that the God who can lift all things cannot lift it?” Worded this way, the inconsistency and meaningless nature of the question is revealed. It’s actually a pseudo-question. It makes no sense. The question itself has no truth value in order to be evaluated as either true or false. It proposes impossible conditions that can never be met. Trying to answer this question is much like trying to answer “What does the color blue smell like?” or telling someone to think about two men, each one taller than the other.
The question also reveals false ideas about the biblical concept of omnipotence. When speaking of God’s omnipotence, Christians are not simply saying “God can do anything at all.” Omnipotence refers to God’s power to do anything which is both consistent with His character and logically possible. The “big rock” question is less about power and more about logic and consistency. God acts in ways that are both reasonable and consistent with His nature. For example, He cannot lie or sin or learn anything new. Those things that are true about His character will always be true, and He cannot do anything to contradict them.
Does it mean the Lord is not powerful because there are things He cannot do? No. It simply means He is a perfect and unchangeable God. Just like He cannot do things that contradict His perfect nature, He also cannot do those things that are logically impossible. For example, God cannot make a square circle. Likewise, it is a logical impossibility-and a nonsensical thing to ask-for God to make a rock so big that He can’t lift it.
This non-question of smug skeptics actually reminds us that we serve a logical, coherent and all-powerful God. Reason andcoherence are hard-wired into the fabric of reality- reflecting the orderlyGod whocreated it. Contradictory questions and meaningless word puzzles which implode on themselves remind us that we will never be able to outsmart the Lord. Nothing we can do and no question we can ask could ever limit the omnipotence and perfect power of our loving Creator.”
To this, I’ll add that the question “Can God make a rock so big that He can’t lift it?” is a logical fallacy because it combines two questions in an illicit way. We should ask”Can God make a rock infinitely heavy?” and “Can God move a rock infinitely heavy?”
Now, notice that I have asked about “heavy” and not “big.” For if we ask “Can God make a rock so BIG that He can’t lift it?” we have an absurdity. For if He can make something so big that takes up all space, there is nowhere to move it to, for it has taken up all space.
But to the questions about heaviness, the answer is that from Alex McFarland, above.