The stock problem of evil is that the existence of evil in the world is incompatible with the Philosophy 101 conception of God, namely that God is all good, all powerful and all knowing. After all, if God has these attributes, then He knows about all evil, should tolerate no evil and has the power to prevent evil. While some take the problem of evil to show that God does not exist, it can also be taken as showing that this conception of God is in error.