They are angels.
Jesus brings with Him only the GT martyrs, the rest of the dead must wait for the GWT Judgment.
Only the faithful Christian peoples will go with Jesus into the Millennium. They will live in peace and prosperity. Psalms 100, 99 and 98
As their names are Written in the Book of Life, they are assured of receiving immortality when they stand before God, on His Great White Throne. AFTER the Millennium.
That's actually a doctrine based on the Jew's old doctrines of a flesh resurrection. Our flesh is not what is raised. Jesus' flesh body was raised, to prove beyond all... doubt that He had risen, and His flesh body was transfigured to "a quickening spirit" Apostle Paul said. Apostle Paul said flesh and blood cannot inherit the kingdom of God.
What actually does God's Word teach about the ORDER of events for the end of this present world, and the appearing of the world to come? Here is that Order...
1. the consuming fire event of 2 Peter 3:10 you are confused about with sun spots, is about God's consuming fire that will completely destroy man's works off the 'surface' of this earth on the FINAL DAY of this present world. Apostle Peter was covering God's previous world-wide destructions upon the SURFACE of the earth. The final one Peter said will be with fire, so that means another destruction upon the SURFACE of the earth like the previous ones He did with waters of a flood. What all will that fire event do?...
a. -- it will literally END this present flesh world, including destroy the flesh bodies of those still alive on earth. So ANY idea of people still in flesh bodies after that future event is just silly, and shows one not staying with the actual Bible Scripture as written.
b. -- that is also the 'day' of Christ's 2nd coming, the only future coming by Christ to end the coming "great tribulation" and gather His faithful Church. That is a POST-tribulational coming and gathering, and not at any other timeframe.
c. -- that event is what Apostle Paul was talking about with those still alive on earth being 'changed' "at the twinkling of an eye". It will be like, poof, and those still alive on earth will suddenly have their flesh cast off, and their "spiritual body" suddenly revealed, while STILL on earth. At that point all peoples... will understand Who God and His Son is. Those who rejected Jesus Christ as Messiah will immediately feel emotional shame, with some of those wishing for the mountains and hills to fall on them.
d. -- that event will also involve Christ's coming in the clouds with His angelic host, the asleep saints that had died that He brings with Him from Heaven, of BOTH Old Testaments and New Testaments.
e. -- at that same moment also, Christ's faithful saints still alive on earth are "caught up" to Him at His coming from Heaven with the asleep saints.
f. -- immediately then, Christ with ALL His saints go to the Mount of Olives east of Jerusalem ON EARTH. Christ's feet touch down upon the Mount of Olives where He ascended to Heaven from, and a great valley is formed there, destroying this coming temple that false-Messiah is to sit in for the coming "great tribulation" prior to His return.
g. -- the wicked dead will also be revealed in spiritual bodies on earth in that same time. Those and the ones still alive who rejected Christ will make up the "nations" of Revelation 20. It will... be a time of teaching and correction by The Word of God. Satan and his host of earthly kings that followed him will be locked in his pit prison throughout that future "thousand years" reign by Jesus and His elect.
h. -- ONLY those of the "first resurrection" will have their 'mortal' souls made immortal. Any believer on Christ that fell away, either because of allowing themselves to be deceived, or by intentional laziness (like the unprofitable servant), will NOT have their 'mortal' souls made immortal. They also, with the wicked, will still have 'mortal' souls liable to perish after the thousand years in the "lake of fire". Only those of the "first resurrection" will have eternal life through Jesus in that time.
2. -- all those, the wicked, the profane, basically those of Revelation 22:15, along with the foolish virgins, will be placed 'outside' the gates of the beloved city (new Jerusalem), for the "thousand years".
a. -- the wicked and deceived will 'stand in judgment' throughout that thousand years, and will be taught the difference between the holy and profane, the clean and unclean. (Ezekiel 44). Only the Just (the Zadok, representing Christ's elect) will be allowed to approach Christ at His table in that time, and serve Him.
b. -- as per Zechariah 6, Jesus Christ the "BRANCH", will build the Millennial temple, which is just for that "thousand years" period.
c. -- at the end of the thousand years, Satan will be loosed one final time to go deceive those nations of unsaved, and lead those who follow him upon the "camp of saints" on earth. God will rain His fire (another fire event) upon those and destroy them and Satan is then cast into the lake of fire.
d. -- then the books are opened to see if any names are found in the Book of Life, and the nations left are judged out of those books. The Book of Life is how one becomes one of Christ's saints with one's name written in it. So this is another check to see if anyone's names from those unsaved nations are written in it, meaning 'some' of those unsaved will... convert to Jesus Christ DURING that future thousand years reign. Those make up the 'implied' 2nd resurrection unto eternal Life in Jesus.
e. -- then the rest judged out of the books not found written in the Book of Life is cast into the lake of fire, which is the "second death". The abode of hell, and death are also cast into that lake of fire.
3. -- then, and only then after that future lake of fire event, is God' literal Kingdom established upon this whole earth, under His Son. And there will be no more literal temple. And it will be an unending existence.
