I learned some interesting details about Philippi. It was 700 miles from Rome in Macedonia. It was a conquered part of the Roman Empire. Conquered cities paid taxes, and its people didn’t have the rights of Roman citizens (talk about a Tea Party waiting to happen). When the Roman army first reached Philippi, Rome was running out of salt to pay their soldiers. Apparently, that’s how they got compensated: salt (Thus the term, “he isn’t worth his salt”.) The soldiers were ready to give up the conquest push. Well, the Philippians wanted to be under Rome’s rule, so they collected as much salt as they could to help the soldiers continue.
For this, Rome granted Philippi full rights as citizens of the Empire: no taxes, all the privileges. A sweet deal. So Paul, then, is writing to the church in Philippi, and has this context running in the back of his head. The people there got it when he wrote Phil 3:20:
But we are citizens of heaven, where the Lord Jesus Christ lives. And we are eagerly waiting for him to return as our Savior.
Another way of translating it would be “we are a colony of heaven.” This makes sense to a people who became a colony of Rome, separated and surrounded by region without the same status. The Philippians were foreigners made citizens. And as citizens of heaven, we receive all the privileges. A sweet deal.