ERROR II: Counting the "1000 years" Millennium not an actual 1000 years
The Millennium, (Latin for "1000 years" as are the Bible's actual words), is a finite period of time with epoch events marking its start and end points:
The "1000 years" Millennium starts with the binding, casting & sealing of Satan into his prison below in the Abyss, (Rev 20:1-3), and with the Resurrection of the Blessed & Holy Ones, (Rev 20:4, the first of the two groups of souls of dead people that are resurrected in Rev 20:4-6).
Following their resurrection, the Blessed & Holy ones reign with Christ throughout the "1000 years" Millennium, (Rev 20:4-6), while Satan remains sealed into his prison in the Abyss below, (Rev 20:1-3 & Rev 20:7).
The "1000 years" Millennium ends with the release of Satan from his prison in the Abyss below, (Rev 20:3 & Rev 20:7), and with the Resurrection of the Rest of the Dead, (Rev 20:5a, the second of the two groups of souls of dead people that are resurrected in Rev 20:4-6).
1 And I saw an angel coming down from heaven, having the key of the abyss and a great chain in his hand. 2 And he laid hold of the dragon, the serpent of old, who is the devil and Satan, and bound him for a THOUSAND YEARS, 3 and threw him into the abyss, and shut it and sealed it over him, so that he should not deceive the nations any longer, until the THOUSAND YEARS were completed; after these things he must be released for a short time.4 And I saw thrones, and they sat upon them, and judgment was given to them. And I saw the souls of those who had been beheaded because of the testimony of Jesus and because of the word of God, and those who had not worshiped the beast or his image, and had not received the mark upon their forehead and upon their hand; and they came to life and reigned with Christ for a THOUSAND YEARS. 5 (The rest of the dead did not come to life until the THOUSAND YEARS were completed). This is the first resurrection. 6 Blesssed and holy is the one who has a part in the first resurrection; over these the second death has no power, but they will be priests of God and of Christ and will reign with Him for a THOUSAND YEARS.7 And when the THOUSAND YEARS are completed, Satan will be released from his prison, 8 and will come out ...