Thinking about God's Plan, or something...?

I was raised a Catholic. My parents and most of my immediate and extended family are devout. I don't understand how I strayed. But I've come to feel that people put too much stock in the whole God thing. It defies logic....in a world that demands it. People are always saying things to the effect of "God has a plan for us all"...."or everything happens for a reason" Does he/it? Why would this God, alleged to be so loving and merciful, allow something like 9/11, or the Holocaust? What's his rationale for innocent young children dying of cancer? I don't want this to sound like an angry rant...so I'll stop there.....but I'd love to hear any of your thoughts.