The city of Philippi
Philippi was a strategic city in Macedonia, in northern Greece, originally known as Krenides (Little fountains). It was developed as a gold mining town by, and named after, Philip of Macedonia, the father of Alexander the Great. It came under Roman control in 168 BC, along with the rest of Macedonia. Philippi became a colony under Augustus, as a result of the Battle of Philippi in 42 BC. After Octavian defeated Anthony and Cleopatra at the battle of Actium in 31 BC, Philippi was properly colonised, with its government and customs modelled on Rome.
In Acts 16:12, Luke describes it as the leading city of Macedonia and a Roman Colony. Its praetors (magistrates) and lictors (magistrates' guards) mentioned in Acts 16:35 are typical of a city administered by Rome.
Philippi was situated on The Egnatian Way, the great highway between the east and west. It's port, Neapolis, where Paul landed, was thirteen kilometres south of the city. It was a predominantly Gentile city, with no Jewish synagogue, so the Jews met outside the city by the river (Acts 16:13).
The church at Philippi
Philippi was the first place recorded in Acts in Europe to receive the gospel, where the first church in Europe was founded by Paul on the second missionary journey, around AD 51 (Acts 16). After having been forbidden by the Holy Spirit to enter Asia and Bythinia, Paul had received a vision at Troas of a man from Macedonia, who called, "Come over and help us".
The significant people Paul and Silas met were: Lydia, the Jewish proselyte, a trader in purple cloth from Thyatira in Asia. She met with other ladies for prayer on the Sabbath by the river. The Lord opened her heart to the gospel, and she and her household were baptised. Paul and Silas then stayed at her house. The second was the slave girl with a spirit of divination, which Paul cast out of her. This event resulted in trouble from the authorities and imprisonment. However there is no record of this girl becoming a Christian. The third was the jailor, who was saved when Paul and Silas were miraculously released from prison by an earthquake while they were praising God.
The church probably met at Lydia's house (16:15,40). Other people associated with the church were Epaphroditus, Euodia, Syntyche and Clement. These are all Gentile names, which would indicate a predominately Gentile church.
Philippi may have been the birthplace and home of Luke (another Gentile Christian), where he practised medicine. He probably stayed behind after Paul left and possibly led the thriving church. The "we passages" in Acts, show Luke joining Paul at Troas and remaining in Philippi until Paul returned there on the third missionary journey six years later (Acts 20:5).
The church in Philippi was probably one of the purest new testament churches, a church that Paul was obviously very fond of. It had a reputation for generosity (2 Cor 8:1-5, 11:9)
Author
There is very little doubt that the apostle Paul was the author.
Where was Paul in prison?
There are three different suggestions: the first is in Rome from AD 61-62 (Acts 28), which is the traditional view. The second is Ephesus, during his third missionary journey (AD 54 - 56), and the third is in Caesarea, during Paul’s trials around AD 58 (Acts 23)
From the letter to Philippi, we know that Paul was in prison (1:7,13,17), and that his imprisonment for Christ was known throughout the whole praetorian guard (1:13). His imprisonment gave the brethren greater confidence and more boldness to speak the Word of God (1:14). There were saints in Caesar's household (4:22). Paul is aware that the verdict could go against him (1:20, 2:17), but expects a favourable verdict soon (1:25, 2:23).
From the Book of Acts, we know that Paul was in prison twice: in Caesarea (23:33 - 26:32) and in Rome (28:16-31). 2 Corinthians mentions other imprisonments at earlier times in his ministry (before the third missionary journey) (2 Cor 6:5, 11:23).
Paul did spend two years in prison Caesarea (Acts 21-23), but there is no evidence for the large Christian community with Paul in Caesarea. Also the letter describes a desperate situation, where the possible outcome was death (1:20, 2:17). In Caesarea, the situation was not desperate, Paul still had the opportunity to appeal to the emperor, which he did (Acts 25). He was expecting a long voyage to Rome, not a visit to Philippi.
The advantage of Ephesus (Acts 19), is that it is only a short distance from Ephesus to Philippi, taking between seven and nine days. The several journeys in the letter would be quite possible. The intended visit to Philippi was fulfilled in Acts 20:1-6. Ephesus was the centre of imperial administration and there would be a praetorium there. However, there is no reference to any imprisonment in Ephesus in NT, although this could be one of the many imprisonments listed in 2 Cor 11. Ephesus would still give Paul the opportunity of appeal to emperor, so would not be such a life-threatening situation. The letter makes no mention of the collection for Jerusalem, which Paul was busy with during the visit to Ephesus, as described in 2 Corinthians.
Paul did spend at least two years in prison in Rome (Acts 28). His appeal to the emperor had already been made, the outcome could be death, with no higher appeal possible. An imminent decision over Paul's death was to be made. Paul mentions the Praetorian guard (Phil 1:13), the imperial body guard for the emperor, which would suggest that he was in Rome. However, it could also refer to the official residence for a governor elsewhere in the empire. He also refers to Caesar's Household (4:22), these were all the employees of the imperial administration throughout the empire, but there were particularly many in Rome. There was a large, well-established Christian community in Rome, which would match this letter.
The disadvantage of Rome was the great distance from Philippi to Rome, 800 miles, which would take seven weeks for each journey, and at least five journeys were implied in the book. News had reached Philippi that Paul was in trouble, possibly as Paul left Caesarea for Rome (4:14), gifts were brought from Philippi to Paul by Epaphroditus (4:18), the Philippian church heard that Epaphroditus was ill (2:26), Epaphroditus heard that the Philippians were worried about him (2:26), and finally Epaphroditus travels back to Philippi with the letter (2:26). However, there would be plenty of time in the two years for these five journeys to be made. The description of Paul in Rome in Acts 28 seems much more relaxed than the tense situation of imminent martyrdom in this letter, but very little detail is given in Acts.
Date
If the Roman imprisonment is accepted, the date will be AD 61-62, probably towards the end of the two year imprisonment.
Occasion of the letter
There is no obvious main theme of the letter and very little doctrine. Paul had several personal reasons for writing the letter. Paul is sending Epaphroditus back, who had been sent from Philippi to bring gifts and to assist Paul in prison. Paul makes it clear that he had not failed in his job, but had become seriously ill and almost died, so that Paul was grateful to God for sparing him. The church had been concerned about Epaphroditus, so Paul was eager to send him back. Paul writes this so that the church would accept him back. This is probably the main purpose of the letter.
Paul thanks them for their gift and continued support in prayer and finances since the church was founded. The church had entered a partnership of sharing with Paul (1:5, 4:15). They had sent Paul gifts while he was in Thessalonica (4:16), in Corinth (2 Cor 11:9), and now in Rome.
Paul encourages the Philippians, who are concerned at Paul's continued imprisonment. Probably they remember his miraculous release from the Philippian prison (Acts 16:25), when the jailor, who is a member of the church, was converted. The church were probably praying for a repeat of the miracle. Paul shows them that the gospel is still spreading in spite of being in prison. His imprisonment has served to advance the gospel (1:12). Paul is confident of release and hopes to visit them shortly (1:19, 2:24), and he plans to send Timothy with news of the verdict (2:23).
There area also a few issues in the church that Paul addresses: there is disunity in the church, Euodia and Syntyche are particularly mentioned (4:2). Paul emphasizes unity and humility, giving the example of Jesus (2:2). He also warns about the Judaizers and the circumcision party who are expected to arrive soon (3:2-3). He also warns against perfectionism, calling them to press on, as they are not perfect yet.
The abrupt change at 3:1
Paul appears to be reaching the conclusion of the letter at 3:1, when there is an abrupt change. Some have suggested that this indicates that the letter consists of two or more fragments which have been put together. Up to four fragments have been suggested. However there is no need to assume the existence of several separate letters, Paul was probably dictating the letter (possibly to Timothy (1:1)), when news reached him of the threat from enemies of the gospel coming to Philippi, hence Paul's warning. There were two threats: from outside the church (3:2-4:1) - the Judaizers, and from inside the church (4:2) - Euodia & Syntyche.
The violent language of 3:2 is followed by Paul resuming his very personal tone at 3:4, which is similar to the rest of the letter. Paul's close relationship with the Philippians shows in chapter three, just as much in the first two chapters. The same themes of joy and rejoicing also appear in 4:1,4,10, and the word "commonwealth" used in 1:27, is also used in 3:20. The letter is almost certainly forms a unit, not being written at different times, although the great hymn of Christ (2:6-11) could well be a quotation of a well-known hymn of the time.