The Paradox of the Stone
Let me tell you about this paradox that a friend in a faith crisis related to me. It goes like this.. if God is omnipotent, he can make the heaviest stone in the world, a stone so heavy even he couldn't carry it. But, also, if God is omnipotent, then he can carry every stone in the world, no stone will be too heavy for him. Therefore, our concept of an all-powerful God cannot make sense. God is either not omnipotent, or God doesn't exist..

The solution goes like this.. God, while omnipotent, is restricted by his very nature. For example, if we acknowledge that God is all-good and loving, then he cannot contradict his very nature by doing something evil. Therefore, God cannot make a stone which he cannot carry because it contradicts his very nature of being omnipotent. God cannot be such that it contradicts his very nature.