The problem of suffering is deeply unsettling challenge to the notion of a god that is both all-powerful and all-loving. Indeed, it is one of the most common arguments used by atheists. Though it does nothing to refute the existence of some sort of god, it certainly poses a deep problem for the Platonic ideal god that appears in classical Abrahamic theism, particularly Christianity. Using suffering language, I shall pose the classical Epicurean tetralemma which outlines the problem rather nicely:
1) Is god willing to prevent suffering but unable? Then he is impotent.
2) Is he able but not willing? Then he is malevolent.
3) Is he willing and able? Then whence cometh evil?
4) Is he neither able nor willing? Then why call him god?
This argument purports to give an exhaustive list of all possibilities. If, indeed, only these four possibilities exist, then it seems an all-loving, all-powerful god is incompatible with the nature of the observed world. Many theists have attempted to answer this challenge by accepting possibility 3) and trying to explain how suffering still exists. The most well-known and popular defense is the so-called "free will defense."
God wants to prevent all suffering, and he certainly could do so, however, he wants even more for humans to have free will, and with free will necessarily comes the capacity to do evil. We need free will because it's important that we choose to obey god rather than simply obey him out of compulsion. This argument has several problems.
What do you think of the problem of suffering/evil? Am I correct in asserting that god must be impotent, malevolent, both, or non-existent, given the proliferate and superfluous suffering which exists in the universe? Comments, questions, additional defenses, etc. are all welcome.