It seems that in despair and hardship it is often quite difficult to distinguish the clouds silver lining. Two people come to mind in the book of Acts. Paul & Silas were in a down time in a down place all while trying to serve Jesus.
It seems that they came around that evening to thank God in song. Which in turn The Lord Jesus shook the foundations physically, and the gaurd on duty spiritually.
What amazes me is why they were excited. They discovered the joy in looking at there plight from God's perspective. He(The Lord) saw they could handle the trial they currently faced (They were stronger than they thought). It was in that they began to be thankful.
Rejoicing comes from taking your circumstances and letting Jesus show you things from His view.
