The sermon, titled "Modeling Faithfulness in the World," uses the Book of Philippians to emphasize the importance of thankfulness and joy in the face of adversity. The speaker, Ted Swinburn, begins with a cautionary tale about the "hidden Christians" of Japan to warn against hiding one's faith to avoid persecution. He encourages the congregation to live out their beliefs publicly, shining like stars in a "crooked and depraved generation" and representing their heavenly citizenship to the world. The central message is that Christians are called to be faithful and to live out their faith publicly, not through their own strength, but through the power of the Holy Spirit, finding peace and rejoicing in the Lord always.