people of Israel were the Kingdom of God in the past.
5.2 This has now been ended, but will be re-established at Christ's return,
5.3 in the form of a world-wide Kingdom on earth, ruled over by Christ on God's behalf.
5.4 The first 1000 years (or 'Millennium') of this Kingdom will see the true believers of all ages ruling over the ordinary mortal people who are alive at Christ's return.
5.5 The Kingdom is therefore not now established politically.
5.6 We are saved by grace through our faith, rather than by our works.