Eternity
The New Heaven and Earth
The New Jerusalem
The New Nations
The Lake of fire
Isaiah 65:17 Isaiah 66:22
1Cor 15:25-28
2Peter 3:13
Revelation 3:12
Revelation Chapter 21 and 22
At the End of the Millennium, Christ will hand the kingdom back over to the Father. The Millennium is therefore the only way that this prophesy can be fulfilled if Christ is to reign at his coming and the believers are to reign with him. The Millennium is the period for which the Believers are differentially rewarded according to what they have done whilst in the body. People who preach amillennialism usually don't preach about the reward of believers and Christ handing things back over to the father once the devil has been thrown into the lake of fire.
2Peter 3:8 says that a thousand years are like a day to the Lord. The old testament has many types and patterns that are seen in the New Testament. God created the world in 6 days and rested on the 7th. We are now 6000 years approximately since Adam. It may be that Christ will reign in the Seventh millennium, after all, the Son of man is Lord of the Sabbath (Matt 12:8 Mark 2:28 Luke 6:5)