Who is included in the first resurrection described in Revelation 20?
The first resurrection includes all believers from the Old Testament, the Church Age, and the Tribulation. Those in this resurrection are not subject to the second death; they will be priests of God and of Christ and will reign with Him for the thousand years.
Les explains that Revelation 20's first resurrection is the resurrection of all the believers—Old Testament, Church Age, and Tribulation saints. On such, the second death has no power. Instead, they will be priests of God and of Christ and shall reign with Him. Les also notes that the thousand years is repeated about six times in six verses, and he compares Scripture with Scripture by turning to 2 Peter chapter 3, verse 8.
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.