There are two resurrections. (And two deaths, Rev. 20:14).
The first resurrection belongs to “the blessed and holy” who will “reign with Christ” for one thousand years. There are three categories–those who sit on thrones with him and have authority to judge, those “beheaded” for the testimony of Jesus, and those who rejected the mark. (Rev. 20:4) Who are the judges judging? The nations. Christ must reign until he has put all his enemies “under his feet” meaning the earth, as God’s footstool (see 2 Chron 9:18). It will bow and confess. It will be subject. Death is the last enemy to be abolished. (1 Cor. 15:25-26) A war of epic proportions is on the horizon. And victory. Then will all be handed back to God the Father at the end (1 Cor 15:24).
The second resurrection is that of the rest of the dead brought before the Great White Throne after the thousand years. These dead are resurrected from three different places: the Sea, Death, and Hades.
Hades is the word the 3rd century B.C. Jewish translators of the LXX chose for Sheol which the NIV likes to translate as the realm of the dead.
Death and Hades get thrown into the lake of fire, the eternal damnation. The Sea does not…. (v.14-15)