I'm sorry but I've not been able to spend much/any time in this forum recently. I've missed a couple of days and there have been about 60 replies in that time, so I'm struggling to keep up with the discussion!
I thought I had answered your question with my previous reply, i.e. I said, "The only people who are promised an immortal nature are Christians who remain overcomers until their death/rapture". The only group (human or angelic) that is promised a change of nature and gaining immortality is Chirstians during what I referred to as the Gospel Age, which ends with the first resurrection when they will be transformed to gain that immortal nature (as a new creation in Christ).
Paul, talking to Christians about what their resurrection bodies would be like, said :
1Cor 15:44) It is sown a natural body; it is raised a spiritual body.
1Cor 15:53) For this perishable body must become imperishable, and this mortal must put on immortality.
Chapters two and three of Revelation are the letters from Jesus to the seven churches. These letters are also prophetic of the church during the Gospel age. Then in Rev. 4:1 John describes a voice from heaven saying “Come up hither, and I will show thee things which must be hereafter”, i.e. he was shown (symbolically) events that will happen at the end of the Gospel age, after the rapture (“Then we which are alive and remain shall be caught up together with them in the clouds, to meet the Lord in the air: and so shall we ever be with the Lord”, 1 Th. 4:17).
John is then shown a vision of the throne of God, and he sees that around the throne there were twenty-four seats, and “upon the seats I saw four and twenty elders sitting, clothed in white raiment; and they had on their heads crowns of gold” (Rev 4:4). These twenty-four elders represent a group, and we know that they cannot be tribulation believers because they are contrasted with them in Rev. 7:13-14. They are not angels because they are contrasted with them in Rev. 7:11 (“all the angels stood round about the throne, and about the elders and the four beasts”). They are not the nation of Israel because they’re distinct from them (Rev. 7 & 12).
Their distinguishing characteristics are that they are on thrones (“To him that overcometh will I grant to sit with me in my throne”, Rev. 3:21), they have white clothes (“He that overcometh, the same shall be clothed in white raiment”, Rev 3:5), they have gold crowns (“be thou faithful unto death, and I will give thee a crown of life”, Rev. 2:10), and they sing the song of the redeemed (“And they sung a new song, saying, Thou art worthy to take the book, and to open the seals thereof: for thou wast slain, and hast redeemed us to God by thy blood out of every kindred, and tongue, and people, and nation; And hast made us unto our God kings and priests: and we shall reign on the earth”, Rev 5:9,10). Note that they’re made kings and priests (and they’re not from Israel only, but from every nation), and only three groups are kings and priests: Melchisidec, Jesus and the Church. John identifies himself and the Church with this group too (Rev. 1:4-6 “John to the seven churches which are in Asia”, “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”). These twenty-four elders clearly represent the resurrected Church.
Note that Rev. 4:5 says “there were seven lamps of fire burning before the throne”, and Rev. 1:20 identifies these, “the seven lampstands are the seven churches” (NIV). So the churches that were on the earth in chapter one are in heaven in chapter four, which is in harmony with chapter four describing events after the rapture.
In the first three chapters of Revelation there are twenty-four titles of Jesus, which are all gentile or church type identifiers. From chapter four on (from the rapture on), the style is very Jewish, e.g. Rev. 5:5 “Behold, the
Lion of the tribe of Judah, the
Root of David, hath prevailed to open the book and to loose the seven seals thereof”, and Rev. 5:6 “stood a
Lamb as it had been slain” – the titles in bold are Jewish titles of the Messiah.
Chapter five describes Jesus unsealing and opening the scroll. Note for later that verse 8 says that the twenty-four elders each had harps, not palms. Chapters 6 to 19 describes the events that will occur in the 7 year period after the rapture (the so-called seventieth week of Daniel, Dan. 9:24-27). Jesus described this period, the “Great Tribulation”, in Mat. 24:14-22, which ends with “except those days should be shortened, there should no flesh be saved: but for the elect’s sake those days shall be shortened”. This Great Tribulation affects the whole world, but particularly it affects Israel, hence in verse 16 He says, “Then let them which be in Judaea flee into the mountains”. This shall be worse for Israel than the Holocaust, during which one in three Jews were killed. According to Zechariah 13:8,9 two out of three shall be killed (“And it shall come to pass, that in all the land, saith the LORD, two parts therein shall be cut off and die; but the third shall be left therein”).
The purpose of the Tribulation is part explained by Hosea 5:15: “I will go and return to my place, till they acknowledge their offence, and seek my face: in their affliction they will seek me earnestly” (ASV). It is the day of the wrath of the Lamb (Rev. 6:16,17), His wrath against them who rejected Him and had Him crucified. It is also described as the day of the LORD, “Neither their silver nor their gold shall be able to deliver them in the day of Jehovah’s wrath; but the whole land shall be devoured by the fire of his jealousy: for he will make an end, yea, a terrible end, of all them that dwell in the land” (Zep. 1:18, ASV). (John says in Rev. 1:10, “I was in the Spirit on the Lord’s day”, i.e. he was about to see things pertaining to this time of tribulation.)
Note that the Tribulation doesn’t begin until the Lamb opens the seal, and the Lamb doesn’t receive the scroll until after the 24 elders have cast their crowns before the throne (Rev. 4:10), so the Church has been raptured or resurrected before the Tribulation starts, and the Church does not go through the Tribulation.
Revelation chapter 6 ends with “For the great day of his wrath is come; and who shall be able to stand?” Then chapter 7 answers that question. It tells that there will be some special servants who will be sealed - “Saying, Hurt not the earth, neither the sea, nor the trees, till we have sealed the servants of our God in their foreheads” (Rev. 7:3). It also tells us “the number of them which were sealed: and there were sealed an hundred and forty and four thousand of all the tribes of the children of Israel” (Rev. 7:4). It then goes on to detail that there will be 12,000 from 12 tribes of Israel (totalling 144,000). They are all Jews.
The work of the sealed servants then results in a lot of people being saved – “After this I beheld, and, lo, a great multitude, which no man could number, of all nations, and kindreds, and people, and tongues, stood before the throne, and before the Lamb, clothed with white robes, and palms in their hands” (Rev. 7:9). As mentioned above, the 24 elders, representing the Church from before the rapture, held harps in their hands (Rev. 5:8), whereas these saved people (now in heaven, before the throne) hold palms. These people are a different group (which is why John didn’t know who they were – Rev. 7:13,14); they are people who are saved out of the Tribulation as a result of the evangelising work of the 144,000 sealed servants from Israel, and they are before the throne of God “and
serve him day and night” (Rev. 7:15).
Rev. 7:17 says that “God shall wipe away all tears from their eyes”. Why were they crying? Probably over lost opportunities. They may regret not having become Christians before the rapture and the Great Tribulation had started, so they missed out on becoming one of the elders, i.e. members of the body Christ and the bride of the Lamb. They missed out on the greater glory of sitting on thrones and reigning as kings and priests.
[I'll continue in a separate reply - this has become too large for one reply!]