Psalm 119:71 (TNIV) "It was good for me to be afflicted so that I might learn your decrees."
If you are going through a hard time, this verse and song might give you some hope.
If you are helping someone go through a hard time, read this psalm - but not to the one you are helping, read it for yourself.
Don't tell people who are going through hard times that God has a reason for their hardships. People have to figure that out for themselves if that truth is actually going to make a difference in their life.
It is probable that some of the hardships you are facing come directly from the hand of God. And it is likely that he has afflicted you with something so that you might no longer go astray, and obey his instructions.
But you, like the songwriter of Scripture, have to figure that out on your own.