Revelation Texts shows there are two resurrections. John does not use the exact phrase “second resurrection,” but he makes the contrast very clear by calling the first one blessed and holy, and then showing a later resurrection for the rest of the dead. Let me explain carefully.
In Revelation 20:4–6, John describes the first resurrection. These are the saints who belong to Christ, who are raised and given life to reign with Him for a thousand years. Verse 6 says, “Blessed and holy is he who has part in the first resurrection. Over such the second death has no power, but they shall be priests of God and of Christ, and shall reign with Him a thousand years.” This resurrection is unto life, victory, and blessing.
But then John says in Revelation 20:5, “The rest of the dead did not live again until the thousand years were finished.” These are those who were not part of the first resurrection. After the thousand years, they are raised, not to reign with Christ, but to stand before the great white throne for judgment (Revelation 20:11–13). This is the second resurrection, though John does not use those exact words. Yet, the very mention of a “first resurrection” in Revelation 20:6 clearly points to a subsequent one. All whose names are not found in the Book of Life are then cast into the lake of fire, which is called the second death (Revelation 20:14–15).