why?

Sometimes i wonder why bad things happen to good people?
Why good people go thru a lot of pain and suffering and the bad people continue to have fun and go out with their "perfect" lives?
Why do good people get sick??why??
Why do we have to see them suffer when all this while they haven't done anything that bad???
You may ask who am i to define who is good and who is bad...well im no one to define that but from my point of view, i only see the good people going through a lot.
I guess God is grinding them to be precious gems.
I may never understand why all this things happen but i have to remember and acknowledge the fact that God works in ways we cannot explain and we may not know why now but it is always done to His best interest towards us.
God, grant me the serenity
to accept the things I cannot change;
the courage to change the things I can;
and the wisdom to know the difference.