Paul writes to early believers from prison telling of all his blessings. How can we be thankful for our blessings when we're in the middle of suffering? How can we give anything when we are in the middle of suffering? Paul shows us that God's blessings rise out of suffering. When we are suffering, we give back to God, knowing / believing that God will still be there when we are through the suffering - whenever that is. So, we celebrate a feast of thanksgiving.