Under the Old Covenant, the nation of Israel was a political entity as well as a spiritual one; it had a territory of its own (given by God Himself), and a king chosen and anointed by God. And as a political kingdom, it had to make laws, raise taxes, and fight wars. However, by the time Jesus was born, Israel had lost her independence and was ruled by nominees of a pagan empire. For many Jews, the promise of a Messiah was bound up with their aspirations for what we would now call “self-determination”. This was probably the main reason for Jesus’ reluctance to use the titles “Messiah” or “Son of David” Himself. (Matthew 16:20) When the crowds of His supporters seemed likely to get carried away, He withdrew until the situation had calmed down again. (John 6:14,15)
Right at the beginning of His ministry, Jesus had faced the possibility of founding a kingdom on earth. The devil had tempted Him with the offer of “all the kingdoms of the world.” (Luke 4:5-8) But at the very end, Jesus said to Pilate: “My Kingdom is not of this world. If it were, my servants would fight to prevent my arrest by the Jews. But now my Kingdom is from another place.” (John 18:36) His Kingdom was not going to be a reconstituted “nation of Israel”. It would have no geographical location, no fortresses, and no armies. It posed no political threat to the Roman Empire (or to any other state), because it would operate on a completely different plane (Mark 12:17). (Of course, it did pose a spiritual threat: it was not long before Christianity clashed with the Empire’s demand for worship of the emperor)
Needless to say, the values of God’s Kingdom are very different from those of the world. Jesus stated them in the Beatitudes. (Matthew 5:3-10) Whereas worldly powers set out to impress and overawe their subjects, Christ came as a servant – and expects the leaders of His people to do the same. (Luke 22:24-27) And whereas the empires of the world seize and maintain their power by force, God’s Kingdom is spread by very different methods. (II Corinthians 10:1-5)
So God’s Kingdom exists within the world, yet separate from it (John 17:15). We are ordinary members of the human race, subject to the governments of the countries we live in as far as ‘secular’ matters are concerned (Romans 13:1-7), yet at the same time we have been “chosen” out of the world (Deuteronomy 7:6, John 15:19) to be “citizens of heaven” (Philippians 3:20). Unfortunately, like Israel (Hosea 7:8, Ezekiel 20:32), Christians have always found it difficult to maintain their distinctiveness. The values and aspirations of the world continually seep into our churches and into our personal lives; hence the repeated warnings in the New Testament to be vigilant and faithful to Christ (e.g. James 4:4,5; I John 2:15-17).
Should Christians get involved in politics? Personally, I think that, in a democracy (where it is impossible to truly divorce oneself from political issues), those who have such a calling should do so – as individuals. We need Christians to be ‘salt and light’ in the political sphere, just as in any other. But we need to recognise that we can’t make people Christian by legislation, any more than we can make them Christian by force. And it tends to be very damaging for churches to get identified with political parties or governments, because people then confuse Christianity with politics – which is precisely not what Jesus intended!