The following presentation is taken from St. Andrew of Caesarea’s commentary on the Apocalypse.
Revelation 20:5-6. 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.
From the writings of the holy Scriptures are we taught that there are two types of lives and two types of deaths. The first life is our current, transitory, and fleshly existence that we are experiencing here on earth as a result of the transgression of Adam and Eve in the Garden of Eden. But thankfully the second life is an eternal life promised to the saints after the heeding and following of the divine and life saving commandments of the Lord Jesus Christ. And in like manner, there are two deaths: one being the death of the flesh in this age and the other through sins leading to the full payment of transgression in the age to come, which is the Gehenna of fire.
We also know that there is a difference among the dead. For on the one hand, there are those to be avoided concerning whom Isaiah says, “They are dead, they shall not live,” (Isaiah 26:14) that is, those bringing stench and death by their conduct, and on the other hand, those praiseworthy ones who in Christ “mortify the deeds of the body,” (Romans 8:13) who are crucified with Christ and are dead to the world. Therefore, those unacceptable dead, those not buried with and raised with Christ through baptism, but those remaining in a state of death by sins, will not live with Him until the completion of the one thousand years, that is, the perfect amount of time extending from Christ’s first coming until His second and glorious coming to judge both the living and the dead.
Since the sinful dead, which have been born from the earth only and not born by the Spirit, they in like manner will return to the earth. Their death becomes the beginning of their future punishment. Those who have a share in the first resurrection, that is, in the rising out of deadening thoughts and mortifying actions, these are the blessed. For the second death will have no power over them, that is, never-ending punishment, but instead, they will exercise priesthood and reign with Christ. As we see it, these things signify to us that from the one thousand years until the loosening of Satan and the deception of the nations, the blessed will not be deprived of the kingdom, but instead more certainly and very clearly will they possess it by the fading away of temporal things and by the ushering in of eternal things.
So then, since there are two deaths, it is necessary to understand that there are also two resurrections. First, then, physical death, which is the inherited penalty for mankind’s disobedience in Eden, whereas the second death is eternal punishment and damnation. The first resurrection is that of being brought to life out of “repentance from dead works,” (Hebrews 6:1) and the second resurrection is the transformation from bodily corruption into in-corruption: on such the second death hath no power.
References:
St. Andrew of Caesarea: Commentary on the Apocalypse. (Washington D.C., USA: The Catholic University of America Press, 2011).
Zondervan. The Holy Bible, King James Version. (Grand Rapids, Michigan: Zondervan, 2009).