Phil. 1:27-30 contains some of the greatest metaphors that Paul uses in all of his writings. The driving word picture is the verb politeuesthe in verse 27. The verb has reference to citizen-soldiers who discharge their obligations faithfully.
With that in mind, here's the paraphrase I've come with so far. See if you like it.
Whatever happens to me personally, remember that there's only one thing that really matters. Yes, I realize that you are Roman citizens and rightly proud of it. But what matters most is the fact that you are citizens of the kingdom of heaven. Continue, then, to exercise your heavenly citizenship in a manner that's in keeping with the duties and responsibilities which that citizenship imposes. Then, whether I'm able to come and see you again or only hear about you, I will keep on hearing good reports about you, especially that you're standing firm in a united spirit, with one mind striving side by side for the sake of the body of faith revealed in the gospel, not frightened or intimidated in any way by those who oppose you. Such courage will be a sign to them of their impending destruction, but also a clear sign to you of your salvation, and that too is from God. For on behalf of Christ, you have been granted the privilege not merely of believing in him but also suffering for his sake. It's now your turn to take part in the battle you once saw me engaged in and, as you hear, I'm fighting still.
I repeat: the crowning part of our task in searching the Scriptures is to discover ways the truth applies to our own life and the lives of others. But it all begins by understanding what the biblical author meant to say to his original audience. My desire is to equip you with what you need to do this. If someday we should happen to meet each other in person and you say, "Dave, let me show you what I discovered about this passage as I dug into its grammar and context," no one will be more excited for you than me!