The Paradox of the Stone
God is all-powerful, or as theologians put it, “omnipotent”; there is nothing that he cannot do. This is part of the definition of “God”.
So can God create a stone that is so heavy that he cannot lift it? Either he can or he can’t.
If God can’t, then he isn’t all-powerful. If God can’t create a stone that he can’t lift, then there is something that he can’t do: create the stone.
If God can create a stone that is so heavy that he can’t lift it, though, then he also isn’t all-powerful. If God can create a stone that is so heavy that he can’t lift it, then there’s something that he can’t do: lift that stone.
There is, therefore, no way of answering the question above that preserves God’s omnipotence. If there is an omnipotent God, then he neither can nor can’t create a stone so heavy that he cannot lift it. This, though, is absurd; he must be either able or unable to perform this feat.
This is the paradox of omnipotence. Many critics of theism have used it to argue that the concept of omnipotence is self-contradictory, that there can be no omnipotent being, and so that God cannot exist.