To understand the parable of Revelation 20 regarding the millennium a person needs to understand that Satan is bound by Jesus (prevented from deceiving them) when the individual Christian is obedient, and loosed to deceive them when they are disobedient.
Re 1:18 I am he that liveth, and was dead; and, behold, I am alive for evermore, Amen; and have the keys of hell and of death.
During times of obedience, they are said to "reign" with Christ. During times of disobedience they do not "reign" in this life, Rm 5:17.
Ro 5:17 For if by one man's offense death reigned by one; much more they which receive abundance of grace and of the gift of righteousness shall reign in life by one, Jesus Christ.
Jesus gives individual Christians the keys to death and Hell. Meaning that they can choose to obey or disobey the commandments of God, Matt 16:19.
Mt 16:19 And I will give unto thee the keys of the kingdom of heaven: and whatsoever thou shalt bind on earth shall be bound in heaven: and whatsoever thou shalt loose on earth shall be loosed in heaven.
To understand this parable or message in Tongues the reader must view the Thousand years as the “obedient Christian life”.
The Greek word Teleo (End – Strongs 5055) is used three times in this chapter. Indicating that the end of something has been reached.
The word is used in this chapter to indicate either the “end” of obedience or the “end” of disobedience.
It is helpful to understand that the Bible tells us that the End/Goal (Teleo 5055) of our faith is Salvation, 1 Pet 1:9. This fact has bearing on this parable and its interpretation.
1Pe 1:9 Receiving the end (Teleo 5055) of your faith, even the salvation of your souls.
Rev 20 verses 2 and 3 begin with Satan being bound. This is the case when a Christian individual lives an obedient life on earth.
Re 20:2 And he laid hold on the dragon, that old serpent, which is the Devil, and Satan, and bound him a thousand years, Re 20:3 And cast him into the bottomless pit, and shut him up, and set a seal upon him, that he should deceive the nations no more, till the thousand years should be fulfilled (Teleo) and after that he must be loosed a little season.
We are told that He will not be loosed until the thousand years are fulfilled or end (Teleo).
This suggests that Satan is loosed when a Christian’s obedience comes to an end.
Verse 4 shows that obeying the Gospel is equivalent to "reigning in this life", Ro 5:17.
Re 20:4 And I saw thrones, and they sat upon them, and judgment was given unto them: and I saw the souls of them that were beheaded for the witness of Jesus, and for the word of God, and which had not worshipped the beast, neither his image, neither had received his mark upon their foreheads, or in their hands; and they lived and reigned with Christ a thousand years.
Verse 5 begins with Satan unbound and deceiving the dead people.
Re 20:5 But the rest of the dead lived not again until the thousand years were finished (Teleo). This is the first resurrection.
Dead people do not live again (participate in the resurrected Christian life, Col 3:1) until their disobedience ends, and Satan is again bound and unable to deceive the people due to their obedience to the gospel of Christ.
In verse 5 "Teleo" is used to indicate that the dead (In sin) do not live again and experience the resurrected life in Christ until the thousand years are finished/accomplished (Teleo).
By using the words "live again" verse 5 illustrates that these people were previously participating in the obedient Christian life before they sinned.
At the point of their "sin," they are referred to collectively as "the rest of the dead".
This concept of being "dead in sin" while being a Christian is sometimes referred to as sleep, as it is in 1 Thess 4:13 and 16.
1Th 4:13 ¶ But I would not have you to be ignorant, brethren, concerning them which are asleep, that ye sorrow not, even as others which have no hope.
1Th 4:16 For the Lord himself shall descend from heaven with a shout, with the voice of the archangel, and with the trump of God: and the dead in Christ shall rise first:
It is seen from Rev 20:5 that when Christians refrain from sin they live the obedient Christian life. They do not live this resurrected life until they are obedient, Col 3:1.
Verse 7 again indicates that when the Christian’s obedience or the millennium expires/ends (Teleo) Satan is again loosed to deceive them.
Re 20:7 And when the thousand years are expired (Teleo), Satan shall be loosed out of his prison,