Several weeks ago, I listened to a shiur on cd from R’ Yitzchak Sorotzkin shlita on Kedushas Beis Haknesses and not speaking during davening. He said over several stories about this. One story was about an individual who’s daughter had cancer, lo aleinu. The doctors had told him that there was no hope for his daughter. A little while later, the man met another Yid and this yid told him that he had a similar problem and he went to a rebbe and the rebbe told him to be mekabel not to talk during davening. He said after several weeks of taking on the kabbala he went back to the doctor and there was no trace of the sickness left. This man heard the story and he took on to be mekabel not to talk during davening and his daughter was healed.
No, we don’t know why things in this world happen. But we can take on extra zechuyos and those zechuyos can fight for us.