Ephesians tells us of the great salvation that is a part of the dispensation of the mystery. But in Philippians we are told to work out that salvation with fear and trembling. So then, Ephesians tells us what we are in Christ, but Philippians tells us what we can do with Christ in us.
One of the things that dates this epistle for us is the mention of Epaphroditus and his illness. Before the end of Acts, Paul could heal all that came to him, and even sent cloths to others who could not see him and they were healed when the cloths were put on them. But this was past and there was no healing from Paul for Epaphroditus.
Another thing that dates it is the confession in chapter 3 that the things which were counted as profitable in the flesh during the Apostolic administration are no longer a ground of confidence, but thrown away as trash. The advantages of Israel in the flesh have passed off the scene.
In 3:11 we find Paul yearning for a resurrection, but before the end of Acts he was expecting to be here and alive when the Lord came to set up His kingdom. So the dispensational frontier has been passed and the coming of the Lord postponed for about 2 days. See Hosea 6:2. Paul probably knew this.
In 3:20 Paul reminds us that our conversation (citizenship) is in heaven, and that it is from this citizenship location that we look for the appearing or manifestation of the Savior, the Lord Jesus Christ. So then, unlike Israel who will look for Him coming in clouds to the earth, we look for His manifestation or coronation in the heavens.
In the past dispensation men were taught to pray and expect an answer to prayer, or to have it done as asked. But that is no longer in order. Here in Philippians we are to pray thusly; "The Lord is at hand (available at a moment's notice), be careful for nothing; but in every thing by prayer and supplication with thanksgiving let your requests be make known unto God. And the peace of God, which passeth all understanding, shall keep your hearts and minds through Christ Jesus." How different from the so-called Lord's prayer of Matt. 6:9-13.
The fact that Paul refers to the Praetorian guard in 1:13 and then expects to be released (his salvation) verse 19 shows that he was in Rome. This is further shown by the fact that many of Caesar's household were slaves, if not all of them, God had put Paul in such a position that he could contact the members of the household of Caesar and give them the good news of the dispensation of the mystery.
It might be well for the reader to outline the 7 steps in the Lord's humiliation
in chapter 2, and then the 7 steps of exaltation which follows. In chapter 3
Paul gives the 7 things which he once thought were an advantage, and the 7 things
he wins in the renunciation of all advantages of the flesh. Then outline the
examples of both Timothy and Epaphroditus who labored with Paul. See the complaint
even then of the lack of those who put Christ first.