“When Jesus began his public ministry, he summarized his entire message this way: “The time is fulfilled, the kingdom of God is at hand; repent and believe the gospel” (Mark 1:15). A new kingdom, a new nation, had been founded and he was now calling people to become citizens of it.”
(Tim Challies) When people translate the New Testament from the original Greek language into modern English, they need to make decisions about how to best communicate the author’s intent. The translator doesn’t only ask “what words did he use?” but also “what did he mean to communicate to his readers?” In Philippians 1:27, most translators have made the decision to use the phrase “manner of life.” That’s a great decision that adds a lot of clarity to our understanding. But behind the phrase “manner of life” is very literally the Greek word for “citizen.” So Paul is literally saying: “let your citizenship be worthy of the gospel.” Why would he say that?
We can do just a little historical digging and find out. Paul was playing off something here that would have made a great deal of sense to those Christians in Philippi. Philippi was a city in Macedonia whose people were mostly Greek, but many years prior, Philippi had become a colony of the Roman Empire. So even though they lived outside of the heart of the Empire, they had been awarded the privilege of Roman citizenship and all the benefits that come with it. They were very proud to be Roman citizens as not every city or colony outside the Empire gained this privilege.