Given that Paul wrote Philippians from a prison cell, it’s striking how often this letter expresses words of assurance. Paul tells the believers that God’s good work in them will be completed (1:6); he anticipates their progress and joy in the faith (1:25); he calls them to find encouragement in Christ and to rejoice in the Lord (2:1, 18; 3:1; 4:4); he reminds them of their heavenly citizenship and the glorious transformation that awaits them (3:20). At several points in Philippians,