I want to stay with my OP. Many, many other issues can be discussed.
This time of the great tribulation is a time of transition from one dispensation to another.
The gospel preached during those days is by an angel supernaturally in the air.
And the contents of that gospel called "the eternal gospel" is one to fear God the Creator.
It is announced from the air by angelic voices to neutralize the threat of Antichrist to worship him as God.
This is in Revelation 14:6,7 -
And I saw another angel flying in mid-heaven, having an eternal gospel to announce to those dwelling on the earth, even to every nation and tribe and tongue and people,
Saying with a loud voice, Fear God and give Him glory because the hour of His judgment has come; and worship Him who has made heaven and earth and the sea and the springs of waters.
The "eternal gospel" which will be preached during the great tribulation (Matt. 24:21) differs from the gospel of grace (Acts 20:24)
preached in the church age. The basic contents of the gospel of grace is repentance toward God and faith in the Lord Jesus (Acts 20:21)
that men may be forgiven of their sins and born again as children of God (Luke 24:47, John 1:12).
The "eternal gospel" is that men should "fear God" and that they may not be deceived to follow Antichrist but be brought back to the genuine worship of God the Creator of the universe. By that time the Creator God will be turning upside down the fores of nature as only God can do.
This Creator God "Who has made the heaven and the earth" is to be feared RATHER than Antichrist who proclaims that he is god.
This proclamation is made from the air supernaturally by an angel. And I saw another angel flying in mid-heaven, having an eternal gospel . . .
At the close of the age this "eternal gospel" that God alone is the Creator who is about to judge is mainly proclaimed bythe angel.
It should remind us of Romans 1:18-20 that human beings should be without excuse to not believe in God the Creator.
For the wrath of God is revealed from heaven upon all ungodliness and unrighteousness of men who hold down the truth in unrighteousness, Because that which is known of God is manifest within them, for God manifested it to them.
For the invisible things of Him, both His eternal power and divine characteristics, have been clearly seen since the creation of the world, being perceived by the things made, so that they would be without excuse;
The terrible effect of Antichrist and his false prophet calls for the announcement of an angel to not be duped to worship Antichrist as god.
Rather He who made the the heaven and the earth is demonstrating in the cosmos that He alone is God.
Men who are forgiven sinners redeemed by grace are priviledged to preach the gospel of grace.
During the great trbulation the main preaching will be from the air angelically to fear God the eternal Creator.
"Fear God and give Him glory" is a commandment given to the earth's dwellers countering the deceit of the false prophet that men should follow Antichrist and the threat of death for any who would not worship him during the great tribulation (Rev. 13:14-15).
We were told that concerning the corporate group of the man-child who is to shepherd the nations with an iron rod with Christ.
And she brought forth a son, a man-child, who is to shepherd all the nations with an iron rod; and her child was caught up to God and to His throne. (Rev. 12:5)
I am surely repeating now. Co-reigning with Christ is a reward. And pre-tribulation rapture of some sleeping and some then living is ALSO a reward.
The promise to be kept h=out of the hour of world wide trial accomapanies the promise that before the overcomers a door
to the kingdom age has been opened which no one can shut.
And to the messenger of the church in Philadelphia write: These things says the Holy One, the true One, the One who has the key of David, the One who opens and no one will shut, and shuts and no one opens:
I know your works; behold, I have put before you an opened door which no one can shut, because you have a little power and have kept My word and have not denied My name. (Rev. 3:7,8)
And with this the promise of pre-great tribulation rapture to these victors.
Because you have kept the word of My endurance, I also will keep you out of the hour of trial, which is about to come on the whole inhabited earth, to try them who dwell on the earth.
I come quickly; hold fast what you have that no one take your crown. (vs. 10,11)
You agreed earlier about the overcoming saints being the builded church which consummates in the New Jerusalem.
Well here is also the promise that they are solidly built into the living temple of the church and will go OUT no more.
They become human transformed "pillars" in God's living house.
He who overcomes, him I will make a pillar in the temple of My God, and he shall by no means go out anymore, and I will write upon him the name of My God and the name of the city of My God, the New Jerusalem, which descends out of heaven from My God, and My new name.
(v. 12)