Which do you believe in, pre-determination or free will? It's pretty important because it shapes your attitude about life and your role in it.
When something bad or untimely happens, it is not uncommon to hear a person say, "I believe everything happens for a reason". Seems appropriately philosophical - a sort of defense-mechanism or a way to vaguely explain the unexplainable or a salve to get through the situation. As an aside, no one says that when something good happens.
"It happened for a reason" seems to imply that God intervened to cause the event in order to test us or teach us a lesson or punish us or to test our faith in him. If that is the case, then it violates the concept of free will - the idea that God has given us the freedom to make choice and that the consequences (pro or con) are directly linked to those choices.
Would God give free will and then randomly intervene - who am I to say.
How to explain an infant dying from a disease - who am I to say.
I believe in free will. I think that other than deciding at what moment we will die, it is very rare that God directly intervenes to change the events of our life (e.g. Moses and the burning bush). By so doing, I take full responsibility for the smart and dumb choices I make, and with God's guidance, I pray that I'll avoid making the really dumb ones.
O.D.O.o.O.D.B.