Dealing with Loss

Some losses in life are self-inflicted. And some losses come at us unexpectedly. What do we do when we are faced with the loss of a loved one, when life is totally out of our control? What do we need to know about God at times like these? Why does He choose to not answer prayers sometimes? How do we handle the loss of a child when we stand helplessly by? What does God want us to know about Him at times like these?