As I've mentioned earlier, the Problem of Evil (POE) is perhaps the biggest single reason why people reject the Christian faith. After all, if you look at all the suffering we see around us (e.g., moral evil like wars and murder, or natural evil such as earthquakes and hurricanes), how can one believe in a perfectly good God?
(And by the way, thoughts and prayers go out to those suffering from the aftermath of the earthquakes in Indonesia.)
One thing about the POE is that you always have to be careful when answering a skeptic's questions about it, because there may be two motivations behind his/her asking. First, it's possible that he or she has a logical, philosophical, or generally intellectual stumbling block to the Christian faith. In that case, one would want to argue clearly and cogently why the fact that evil exists in this world does not invalidate Christianity.
On the other hand, the skeptic could be looking for emotional answers. For example, if they have been hurt deeply recently, or wronged by some personal crime, then presenting a logical argument about why God may exist in light of evil in this world may not be much help. Expressions of love, hope, comfort, and acceptance may be more appropriate in these cases.