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.
Revelation 20:4-6

The following is from a post on this blog back in June of 2006

Those John sees on the throne are most likely the saved of God. It could be that John saw the twenty four elders on the thrones, but that does not negate the above statement if we keep in mind that the “elders” represent the redeemed. A great emphasis is placed upon the martyrs. Saints who gave their physical lives for Jesus during great trials and persecutions.
Sometime shortly after the fall of Babylon – religious, economic, political – those who die for Jesus during the Great Tribulation are resurrected and given new bodies. These are the last to be resurrected before the millennium begins. These are the ones who have part in the “first resurrection” along with all those who were raptured at the beginning of the tribulation. The “first resurrection” began with the bodily resurrection of Jesus, and others who came out of their graves also (Matthew 27:51-53). A third group to be raised – of the “first resurrection – are those who “died in Christ” before the time of “Jacob’s trouble” (the tribulation period). This will take place at the rapture when both the dead and living [in Christ] will be “caught up together” (1 Thes. 4:16-18).
In verse six we find the fifth of the seven Beatitudes in the Revelation. “Blessed [Happy] and holy is he that hath part in the first resurrection:…” The promise is that “the second death” – eternal damnation will have no power, no affect, or effect on them. What a blessing it is. Those who have part in the first resurrection will be “priests of God and of Christ, and shall reign with Him a thousand years”.