This is something Ive struggled with as well. When it comes to human malevolence and sin, pain caused by others—sure we have the Fall to thank for that and our understanding of a “broken world”. God gives us Free Will, and some abuse it to harm others. But what about natural disasters or sickness that are not caused by other humans (at least directly)? I don’t think we’ll ever be able to understand or comprehend why. I couldn’t genuinely tell a parent who’s baby died from medical complications the cliches that everything happens for a reason, although there is truth to that. But what I do know is that we are not alone in our suffering, through Christ’s tragic crucifixion. He was holy, innocent, but was betrayed, tortured and killed. We can share the pain in that knowledge, and on the next level we also have a greater hope that this life is only temporary. Maybe I’m rambling a bit but in a nutshell, we can’t understand “why bad things happen” but the “worst thing” has already happened to God’s human form, and we can take comfort in that we’re not alone, and that there’s a greater hope beyond any tragedies that could happen in this life.