Post-Tribbers like to insist that Revelation 20 tells us when the First Resurrection happens. I
Resurrection happens at the Seventh Trumpet, and we see Resurrected
Church Believers in the Heavenly Zion in chapter 14.
It is the saints seen
in Chapter 15 who are most directly defined as those being refereed to
in Chapter 20 as reigning with Christ during The Millennium. It is an inherently specific group, only those Marytered by The Beast, unless your an Historicist, you can't say that refers to all Believers.
term "first resurrection" is a classification more so then a sequence. Like Amalek being called the First of the Nations in Numbers 24:20, when as a bastard grandson of Esau he was no where near the first to come into existence. Or saying something is First Class.
begins with Jesus, then those Matthew 27:51-53 refers to as rising soon after
Jesus did. Then The Church at The Rapture, and then those incorrectly
called by pre-tribbers 'Tribulation Saints" in chapter 20.
This goes back to my many
other posts on The Resurrection.