Letter of Paul to the Philippians, also called Epistle of Paul the Apostle to the Philippians, abbreviation Philippians, eleventh book of the New Testament, written by St. Paul the Apostle to the Christian congregation he had established in Philippi. It was penned while he was in prison, probably at Rome or Ephesus, about 60-61 C.E. Paul's primary purpose in writing this letter was to thank the Philippians for the gift they had sent him upon learning of his detention at Rome (1:5; 4:10-19). However, he makes use of this occasion to fulfill several other desires: (1) to report on his own circumstances (1:12-26; 4:10-19); (2) to encourage the Philippians to stand firm in the face of persecution and rejoice regardless of circumstances (1:27-30; 4:4); (3) to exhort them to humility and unity (2:1-11; 4:2-5); (4) to commend Timothy and Epaphroditus to the Philippian church (2:19-30); and (5) to warn the Philippians against the Judaizers (legalists) and antinomians (libertines) among them (ch. 3).