Thanksgiving and Joy. 1st Thessalonians 3:9 Paul’s evangelistic work was successful and impactful in the lives of the believers in Thessalonica. He thanked God for what the Lord had done, even though he felt his gratitude was inadequate considering the results of God's work in those who heard His word. Paul did not take any credit for the well-done work on his part but instead expressed his joy at what God had accomplished.
When we “render” something, as used in this context, it means “recompense” or “What can we do to pay God back for all the joy I have because of you?” Joy and life are linked, contrasting sorrow and death. Yet, when we experience deep sorrow, it broadens our capacity for joy and makes joy more meaningful when it returns. When we earnestly pray for those who concern us and hear of their light and lives lived for God and His glory, our joy exceeds what it was before the times of anxiety.
How grateful we are when we hear about the advances of the Gospel and God's work happening through the brothers and sisters we know! Some are in remote parts of the world, speaking languages we don't understand, yet God is working through them. What joy it brings during a prayer meeting when God's people hear about His work flourishing in distant places, even if it seems to be slowly declining here. We can understand Paul's desire to go there and be with them in the spreading of the work in Macedonia, Achaia, and other regions. Joy and gratitude before God are often the only ways we can share in the work of others.