The translators of the King James Bible used the English word "conversation" in 18 passages, among which are five different Greek terms. Most of the words would be understood by our modern idea "manner of life" or behavior. However, in today's verse, the word is politeuoma, derived from another Greek word, polites. Our English word "politics" comes from that, especially in the sense of citizenship as it relates to governmental oversight.
The apostle Paul is the only New Testament writer to use the "politics" word, and he does so only two other times. On one occasion, "all Jerusalem was in an uproar" (Acts 21:31) over Paul's supposed violation of the Temple. After giving testimony of his conversion and subsequent ministry to the unruly crowd, Paul said, "Men and brethren, I have lived [politeuomai] in all good conscience before God until this day" (Acts 23:1), simply and boldy declaring that he now lived as a citizen of heaven.
Earlier in his epistle to the Philippian church, Paul had challenged them, "Let your conversation [politeuoma] be as it becometh the gospel of Christ: that whether I come and see you, or else be absent, I may hear of your affairs, that ye stand fast in one spirit, with one mind striving together for the faith of the gospel" (Philippians 1:27). Paul's challenge is just as clear to us: Live and think like our citizenship is in heaven.
Heaven's rule may be best understood by our English word "commonwealth," a political community founded for the common good. We are "joint-heirs" with Christ (Romans 8:17), and we should look "for a city which hath foundations, whose builder and maker is God" (Hebrews 11:10). HMM III