We believe that the thousand years span the time between the first and second resurrections.
“At the coming of Christ the wicked are blotted from the face of the whole earth-consumed with the spirit of His mouth and destroyed by the brightness of His glory.” -The Great Controversy, p. 657. 2 Thessalonians 1:6-8; 2:8; Isaiah 24:12, 22.
During this time no more human life will exist on this earth. As a result of mighty natural catastrophes, the earth will be in a condition of complete desolation. Jeremiah 4:23, 24; 25:32, 33.
“During the thousand years, the saints live and reign with Christ in heaven and judge the fallen angels and the wicked. The earth will be desolate. Only Satan and his angels will live here.” -The Great Controversy, p. 659; Revelation 20:1-3.
At the end of the thousand years, Christ will descend to our earth with all the saints. Then the wicked will be resurrected from the dead. After that, the Holy City will come down; and Satan and his angels, with the resurrected wicked, will encircle the Holy City. God will send fire from heaven, and sin and sinners will be forever destroyed, through which the earth will be cleansed. Revelation 20:4, 5, first part, 7-10; Malachi 4:1, 3.