Atheists are fond of arguing that because there is evil in the world, God doesn't exist. And it has just as often been replied that the conclusion doesn't follow for several reasons (for example, a good God might have loving reasons for permitting suffering). And it has also been pointed out that if God doesn't exist, there is no "problem of evil," since there is no evil, only experiences and phenomena that we personally dislike. Evil implies a cosmic standard, and without a transcendent God, we can have no cosmic, universal, or even global, standards of value, and hence no way of arguing against the existence of God because of the presence of evil.
It has also been pointed out that if we got here by some purely naturalistic process (like evolution), how could we trust our brains to know that? If evolution chooses mutations on the basis of the reproductive advantage they offer the organism, then our brains developed not to understand truth or the reality either the natural or moral world, but merely in order to outreproduce every other human. So our perceptions of the external world, our use of reason, our analysis of our experiences--all are suspect and unreliable.
Further, and this has also been remarked, if we are merely evolved animals, where all that exists is a brain with various electrochemical events (no mind, no soul, no spirit), then there is not really a you or me to experience evil, only a deterministic brain, And if we our brains determine randomly or determine deterministically what we believe and do, then perhaps atheists are randomly required to disbelieve in God, while we theists are equally randomly required to believe. Why (and how) argue with beliefs that are predetermined by the purposeless activity of our brains? Why try to change someone's beliefs when those beliefs are an accidental product of a random cosmos?
Why not adopt the eastern idea that suffering is maya, an illusion, and not real at all? What happens to the atheist argument then? What problem of pain?