The verb tenses are all aorist indicative active:
Revelation 20:4 and those who
had not worshiped (aorist indicative active) the beast or its image and
had not received (aorist indicative active) its mark on their foreheads or their hands and they
lived (aorist indicative active) and
reigned (aorist indicative active) with Christ for a thousand years.
These who did not worship the beast or receive the mark, lived and reigned with Christ. This is the 1st resurrection.
Revelation 20:5 This is the first resurrection
The 1st resurrection is when the believers are priests of God and Christ
Revelation 20:6 Blessed and holy is the one who shares in the first resurrection! Over such the second death has no power,
but they will be priests of God and of Christ, and they will reign with him for a thousand years.
The believers in Peter and John's day were already a kingdom of priests
1 Peter 2:9 But you are a chosen race, a royal priesthood,
Revelation 1:6 and made us a kingdom, priests to his God and Father,
Revelation 5:10 You have made them to be a kingdom and priests to serve our God, and they will reign
b on the earth.” (notice the b, which indicates some manuscripts state 'they reign').
Thus the 1st resurrection (born again) was already happening in Peter and John's day.
You are assuming that John is seeing the physical resurrected souls living and reigning, in their new spiritual bodies, with Christ in in a future tense on earth. However the verb tenses tell another story. John is seeing the souls of those having been beheaded (perfect participle) for the testimony of Jesus and those who did not worship (past tense) the beast, did not take (past tense) its mark, who lived (past tense) and reigned (past tense) with Christ.
I disagree, the believers in Peter and John's day were already a royal, kingdom of priests. This was before the coming of Christ:
1 Peter 2:9 But you are a chosen race, a royal priesthood,
Revelation 1:6 and made us a kingdom, priests to his God and Father,
Revelation 5:10 You have made them to be a kingdom and priests to serve our God, and they will reign
b on the earth.” (notice the b, which indicates some manuscripts state 'they reign' which is presently, not just in the future).
Which leads me to believe that being born again is the first resurrection, as those born again pass from death to life and are a new creation, as well as a kingdom of priests. Does the 2nd death have power over those born again? No.
I agree that they are reigning on earth:
Luke 10:19 have given you authority to trample on snakes and scorpions and to
overcome all the power of the enemy; nothing will harm you.
John 14:12 Very truly I tell you, whoever believes in me will do the works I have been doing, and they
will do even greater things than these, because I am going to the Father
I believe that all those who receive Gods gift of righteousness reign in life through Christ.
Romans 5:17 For if, by the trespass of the one man, death reigned through that one man, how much more will those who receive God’s abundant provision of grace and of the gift of righteousness reign in life through the one man, Jesus Christ!