Twelve is the symbolic number of God's church; the church was organized under twelve tribes in the Old Testament, and twelve apostles in the New. The "144,000" John saw in heaven ("twelve times twelve times one thousand") is a symbolic number for the full number of the saved from both Old and New Testament. What symbolism is involved in this matter?
And I looked, and, lo, a Lamb stood on the mount Sion, and with Him an hundred forty and four thousand, having His Father's Name written in their foreheads.
And I heard a voice from heaven, as the voice of many waters, and as the voice of a great thunder: and I heard the voice of harpers harping with their harps:
And they sung as it were a new song before the throne, and before the four beasts, and the elders: and no man could learn that song but the hundred and forty and four thousand, which were redeemed from the earth.
AN AMILLENNIAL EXPLANATION OF REVELATION 20:1-15
And I saw an angel come down from heaven, having the key of the bottomless pit and a great chain in his hand.
And he laid hold on the dragon, that old serpent, which is the Devil, and Satan, and bound him a thousand years,
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: and after that he must be loosed a little season.
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.
But the rest of the dead lived not again until the thousand years were finished. This is the first resurrection.
Blessed and holy is he that hath part in the first resurrection: on such the second death hath no power, but they shall be priests of God and of Christ, and shall reign with Him a thousand years.
The first verses of this chapter present a heavenly scene, not an earthly one. No mention is made of matters on earth until verse seven. The chapter is located in Revelation, a book full of symbolic representation. We can determine that this portion of Scripture is also symbolic and not literal from its opening verses. The "key," "bottomless pit," "great chain," "dragon," and "old serpent," are all symbolic terms. Literally, Satan is not a dragon or serpent and as a spirit he cannot be literally bound with a chain and locked in a bottomless pit.
Due to the symbolic context, the "thousand years" should also be interpreted symbolically as "ten times ten times ten," the fullness of time as appointed by God. For other symbolic uses of a "thousand years" in the Book of Revelation, refer to Revelation5:11,7:4-8,9:16, 11:3, 11:13, 12:6, 14:1, 14:3, 14:20,20:2-7,21:6. In fact, all twenty-eight references to a "thousand" in the book of Revelation are symbolic.
Scripture tells us that the meaning of Satan being bound is "that he should deceive the nations no more." Until Pentecost Satan was able to deceive the nations of the world (except Israel) by keeping the Word of God from them. Satan kept nations in spiritual darkness. They never saw the light of God's gospel. In the last days (the New Testament times) this would change. Satan would be bound, powerless to stop the light of God's gospel from going to all nations, tribes, and people on earth, until the "thousand years," the fullness of the "gospel time" is fulfilled. Then Satan shall again be loosed for a short time to deceive the nations and to lead them back into the darkness of idolatry and heathendom.
Verse four refers to souls of the saints (not physically resurrected saints) living and reigning with Christ in heaven (Christ does not descend to earth until verse eleven in this chapter). The souls of the saints, those who did not serve the god of this world, live and reign with Christ in heaven until the "thousand years" (the fullness of time) is reached.