Revelation 7:4 And I heard the number of them that were sealed, a hundred and forty and four thousand, sealed out of every tribe of the children of Israel:
Verses 5 thru 8 are the names of the twelve tribes
Re 7:9 After these things I saw, and behold, a great multitude, which no man could number, out of every nation and of all tribes and peoples and tongues, standing before the throne and before the Lamb, arrayed in white robes, and palms in their hands;
Re 7:10 and they cry with a great voice, saying, Salvation unto our God who sitteth on the throne, and unto the Lamb.
Re 7:11 And all the angels were standing round about the throne, and about the elders and the four living creatures; and they fell before the throne on their faces, and worshiped God,
Re 7:12 saying, Amen: Blessing, and glory, and wisdom, and thanksgiving, and honor, and power, and might be unto our God for ever and ever. Amen.
Re 7:13 ¶ And one of the elders answered, saying unto me, These that are arrayed in white robes, who are they, and whence came they?
Re 7:14 And I say unto him, My lord, thou knowest. And he said to me, These are they that come of the great tribulation, and they washed their robes and made them white in the blood of the Lamb.
First, we have to remember, The tribulation isn't for the gentiles, yet there will be plenty alive during that time, those that miss the rapture. For these 144,000 are commanded by God after the rapture to spread the gospel during the middle of the first half of the tribulation.
Re 14:1 ¶ And I saw, and behold, the Lamb standing on the mount Zion, and with him a hundred and forty and four thousand, having his name, and the name of his Father, written on their foreheads.
Re 14:2 And I heard a voice from heaven, as the voice of many waters, and as the voice of a great thunder: and the voice which I heard was as the voice of harpers harping with their harps:
Re 14:3 and they sing as it were a new song before the throne, and before the four living creatures and the elders: and no man could learn the song save the hundred and forty and four thousand, even they that had been purchased out of the earth.
Re 14:4 These are they that were not defiled with women; for they are virgins. These are they that follow the Lamb whithersoever he goeth. These were purchased from among men, to be the firstfruits unto God and unto the Lamb.
Re 14:5 And in their mouth was found no lie: they are without blemish.
The 144,000 in conjunction with the two witnesses and the Angels proclaiming the Gospel. In response to their testimony, a large number of people will come to faith in Christ, although many will be martyred. Which is the multitude you read in Re.7:9. This multitude is the ones who under the throne, mention in Revelation 6. Once the 144,00 the two witness and the Angelic proclamation of the Gospel is completed and those of the human multitude die or are martyred are the ones who will fulfill their course in Re:9:11. Which is where Re 7:9 comes in, the 144,000 jews have fulfilled their course and the martyr's of old, before and during the rapture are released into the throne room.
Revelation 6:9-11 And when he opened the fifth seal, I saw underneath the altar the souls of them that had been slain for the word of God, and for the testimony which they held: and they cried with a great voice, saying, How long, O Master, the holy and true, dost thou not judge and avenge our blood on them that dwell on the earth? And there was given them to each one a white robe; and it was said unto them, that they should rest yet for a little time until their fellow-servants also and their brethren, who should be killed even as they were, should have fulfilled their course.
Yeah, I know this can be confusing. Because Revelation doesn't necessarily translate chronologically in some cases, due to what is going on In the throne room. Many of the things that John is told to write down happen at once and then it slows down at times. This just shows the power of God's prophetic way and how the Word of God stands on its own.
Sorry, I know you weren't knocking anything. I just real exited to know that I'll witness these things and pray. Even so Lord, Come!!