The Millennial Reign
The Millennial Reign is a 1,000 year period defined in Revelations starting from the time when the Lord comes and takes His redeemed to the paradise of Heaven (the Second Coming), to the time the Lord returns to the desolate earth with His chosen people in the holy city (the New Jerusalem.) The 1,000 years is also a time of adjustment needed for God's people, in that they will come to understand why the wicked (or quite simply, those who did not choose Christ) were blotted out from the Book of Life. This places a great emphasis on the Word getting out to people, as there are no second chances for those who don't accept Christ and repent. This time is "valuable time", and the existence of the Millennial Reign proves this. There will be tinges of sadness for those whose loved ones are not in the Kingdom of God, but over time the Lord will show them that His judgments are righteous, and that everyone selected for the second resurrection deserves the end fate of the Lake of Fire which will destroy all sin.