Paul writes Philippians from prison, yet the letter is full of joy, specifically in regards to knowing Christ and the hope of the gospel. Paul thanked God daily for the generosity of the Philippians, and for their acceptance of the gospel. He was sure that “he who began a good work in you will bring it to completion at the day of Jesus Christ”, and the same applies to us.
Paul promotes the idea of unity and of service, “Let each of you look not only to his own interests, but also to the interests of others”, just as Christ took the form of a servant. Paul followed his own advice, even to the point of choosing service over escape from his present suffering, “I know that I will remain and continue with you all, for your progress and joy in the faith”.
Paul also reminds the Philippians that God was working in their lives, “it is God who works in you, both to will and to work for his good pleasure”, and consequently “you also should be glad and rejoice with me”. They were children of God, and as such they would “shine as lights in the world, holding fast to the word of life”.