For I am not ashamed of the gospel, for it is the power of God for salvation to everyone who believes, to the Jew first and also to the Greek. Rom. 1:16 (NASB)
The early church was being heavily persecuted and in their suffering they were reminded to praise God. They were chosen by God to salvation even though the world hated them. They were called to obey as a result of God's work in their lives. When they were discouraged by things in this life, they could rejoice in the wonderful eternal inheritance of heaven.