Paul and Timotheus, the servants of Jesus Christ, to all the saints in Christ Jesus which are at Philippi, with the bishops and deacons: Paul and Timotheus - That Timothy was at this time with the apostle in Rome we learn from Philippians 2:19, and also that he was very high in the apostle's estimation. He had also accompanied the apostle on his two voyages to Philippi, see Acts 16 and 20., and was therefore deservedly dear to the Church in that city. It was on these accounts that St. Paul joined his name to his own, not because he was in any part the author of this epistle, but he might have been the apostle's amanuensis, though the subscription to the epistle gives this office to Epaphroditus. Neither in this epistle, nor in those to the Thessalonians and to Philemon does St. Paul call himself an apostle; the reason of which appears to be, that in none of these places was his apostolical authority called in question.
Bishops and deacons - Επισκοποις· The overseers of the Church of God, and those who ministered to the poor, and preached occasionally. There has been a great deal of paper wasted on the inquiry, "Who is meant by bishops here, as no place could have more than one bishop?" To which it has been answered: "Philippi was a metropolitan see, and might have several bishops." This is the extravagance of trifling. I believe no such officer is meant as we now term bishop.