Why does God allow (supposedly) godly people to hit financial rock bottom?

I was reading a story the other day about a Christian family who suffered financial ruin, but still praised God because God upheld them in their time of crisis. But why did God permit this family to suffer financial ruin in the first place? I'm sure that they prayed to him in their time of need. I believe in God, but just wonder why God allows Christians or devout Jews (etc) to suffer.