About four or five years after his last visit to Philippi, while a prisoner at Rome, Paul received a delegation from the Philippian church with a conribution and Epaphroditus to minister to Paul's needs. Unfortunately Epaphroditus suffered a near-fatal illness. Accordingly, Paul decided to send him back to Philippi and wrote this letter to send back with him.
Find out more in Philippians: Christ, the Source of Joy and Strength. Twelve lessons with commentary from John MacArthur.