In Revelation 6:9, John saw souls under the alter that were slain for the word of God and the testimony which they held. They were given white robes and told to rest until the remainder of their fellow martyrs were killed. In 7:14-15, more white robed people who have come out of the Tribulation are seen by John. They will serve Him in His temple, and live with Christ. Then, in Revelation 19:8, the Bride of Christ are arrayed in fine linen entering the Marriage Supper of the Lamb.
My question, in Revelation 20:4, I understand it to mean that only the martyrs of Christ will reign with Him one-thousand years. Will all saints reign and rule with Him, or only the martyred saints from the Tribulation period?
Revelation 1:5-6(KJV) says:
Unto him that loved us, and washed us from our sins in his own blood, and hath made us kings and priests unto God and his Father; to him be glory and dominion for ever and ever. Amen.
It was written to the Church. This same language is also seen in Revelation 5:9-10, the so-called Song of the Redeemed. The church is in view there as well.
Tribulation martyrs serve the Lord in His Temple. (Revelation 7:14-15) It’s a priestly role. They aren’t ever referred to as kings.
Revelation 20:6 says that they will be priests of God and will reign with Him, but only the Church is given the status of royalty (1 Peter 2:9) and granted a seat at the Lord’s side on His Throne. (Ephes 2:6)
Therefore both groups will assist the Lord in His eternal rule, each according to its assigned role.