It may help us to look first at the historical idea of kingship that shaped Israel’s identity in the Old Testament. Jews believed that the coming of God's kingdom meant the destruction of Israel’s national enemies (Persia, Greek, Rome...).
Only gradually would Israel understand that Yahweh’s kingdom would come through the defeat of humanity’s real enemies: sin and death. The kingdom of God would be made known not in power but in humility, not in domination, but in forgiveness. True kingship would come through the ministry, death and resurrection of Jesus.
Perhaps Christ’s own words provide the best clue to our understanding of kingship: “My kingdom is not of this world.” And thank God! When we examine contemporary political structures we recognize their shortcomings and the many ways governments fail their people.
God’s kingdom is not of this world. God will never fail us nor renege on the promise of eternal life. In the heavenly kingdom the faithful will live in the fullness of God’s glory. It will be a peaceable kingdom beyond human construction or imagination.
Is God’s kingdom something we have to wait for, some future event? Not at all. God’s kingdom may not be of this world, but it is in this world. The Lord tells us that the kingdom of God is within us.
We may need to live within a human political structure with all its ramifications for good or evil. But our true life is one lived out of the kingdom already within our hearts, within our midst, brought to fulfillment in eternity.