In Revelation 7:13-15 there is a Group of Believers who “came out of the Great Tribulation” who SERVE God. In Revelation 20:4-6 there are those who are beheaded for Christ, therefore, they reign with Christ. What is the difference between the 2 Groups of Believers?
Could it be that the 1st Group are the Christians who missed the Rapture by “living in sin” at the time of the Rapture? and that the 2nd Group are new converts who were faithful to Christ?
To one degree or another, all of us are living in sin. Due to our sin nature, it’s impossible for us to be living otherwise. But all of our sins were forgiven at the cross (Colossians 2:13-14) and by that once for all time sacrifice we’ve been made perfect forever in God’s sight (Hebrews 10:12-14). Therefore no born again believer can miss the rapture due to sinfulness.
The group who arrives in heaven in Rev. 7:13-15 consists of believers who will come to faith after the rapture. They will die during the seal judgments before the Great Tribulation begins. We know they are not part of the Church because while their destiny is to serve God in His Temple, they are not called priests.
The group that is resurrected in Rev. 20:4-6 consists of post-Church believers who will be beheaded during the Great Tribulation for refusing to take the Mark of the Beast. We know they are not part of the Church because their resurrection takes place at the time of the 2nd Coming, and because while they will reign with Christ they are never called kings.
Only the Church is described as being kings and priests. I believe these two groups will assist in the administration of the Millennial kingdom in a way that’s somehow subordinate to the Church.