Here are Piper’s reasons for speaking about "When the Righteous Suffer" as he opened up with tonight.  This was basically his introduction. 

1.  Hundreds of you have suffered and are looking for a way out of the darkness.
2.  You suffering is coming for sure.
3.  Persecution (he lists everything from scorn to cancer to calamity). they’re all the same with regard to two things. a) the design of the devil to destroy faith  b) the design of God to strengthen your faith
4.  Natural disasters have put theophany in the news.
5.  God is rejected wholesale by many because of suffering.
6.  Christian critics of the sovereignty of God
7.  The wise, good, just, absolute sovereignty of God is great beyond all measure.
8.  Suffering is appointed as one way for the gospel to spread.
9. The supreme value, and glory, and admirableness of Christ is known when people see Him as more valuable than anything we could lose.

Here’s one more nugget:  In regard to why good people suffer.  "Earth will never give you an answer.  Heaven will."