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)