Twelve thousand of twelve tribes of Israel were sealed
Rev 7:5 Of the tribe of Juda were sealed twelve thousand. Of the tribe of Reuben were sealed twelve thousand. Of the tribe of Gad were sealed twelve thousand.
God knows who is from each tribe listed. There are no longer records kept, but He knows. These are all Jews, not the Church. The church many believe would have been taken up to be with Jesus. These chosen of Israel are sealed by God in their foreheads, the mark of ownership as we were sealed by His Holy Spirit. Jesus was sealed by God and then through him we were sealed.
John 6:27 Labour not for the meat which perisheth, but for that meat which endureth unto everlasting life, which the Son of man shall give unto you: for him hath God the Father sealed.
2 Cor 1:21 Now he which stablisheth us with you in Christ, and hath anointed us, is God;
2 Cor 1:22 Who hath also sealed us, and given the earnest of the Spirit in our hearts.
Rev 7:6 Of the tribe of Aser were sealed twelve thousand. Of the tribe of Nephthalim were sealed twelve thousand. Of the tribe of Manasses were sealed twelve thousand.
Rev 7:7 Of the tribe of Simeon were sealed twelve thousand. Of the tribe of Levi were sealed twelve thousand. Of the tribe of Issachar were sealed twelve thousand.
Rev 7:8 Of the tribe of Zabulon were sealed twelve thousand. Of the tribe of Joseph were sealed twelve thousand. Of the tribe of Benjamin were sealed twelve thousand.
The tribe of Dan is not listed, perhaps because they were into idolatry. The tribe of Joseph is listed, actually his two sons were of the tribes: Manasseh was listed, the other was Ephraim, which also was into idol worship. Those chosen were sealed on their foreheads, which included a new heart, perhaps a change of mind indicated, or an outwardly visible seal to mark them for the angels and for man.
They seemed to be protected and triumphant through the period of God's wrath, meeting with Jesus at Mount Zion at His return (Revelation 14:1).
They are celibate (Revelation 14:4).
They are the beginning of a greater harvest (Revelation 14:4).
They are marked by integrity and faithfulness (Revelation 14:5).(Guzik)
These were sealed after the church was caught up; but they will be included with the church as God's redeemed. Paul was perhaps symbolic of these chosen ones. He was not with the original twelve apostles and yet Jesus chose him and sealed him as an apostle to the Gentiles, as one born out of season.
1 Cor 15:8 And last of all he (Jesus) was seen of me also, as of one born out of due time.
1 Cor 15:9 For I am the least of the apostles, that am not meet to be called an apostle, because I persecuted the church of God.
1 Cor 15:10 But by the grace of God I am what I am: and his grace which was bestowed upon me was not in vain; but I laboured more abundantly than they all: yet not I, but the grace of God which was with me.
The church of mostly Gentiles must come to it's fulness and then Israel has it's time.
Rom 11:25 For I would not, brethren, that ye should be ignorant of this mystery, lest ye should be wise in your own conceits; that blindness in part is happened to Israel, until the fulness of the Gentiles be come in.
Rom 11:26 And so all Israel shall be saved: as it is written, There shall come out of Sion the Deliverer, and shall turn away ungodliness from Jacob:
Rom 11:27 For this is my covenant unto them, when I shall take away their sins.