First, when do the 144,000 appear on the scene?
During the tumultuous period of The Seven Seals, after the sixth seal, and before the seventh, we read from Revelation 7:1-8 -
"After this I saw four angels standing at the four corners of the earth, holding back the four winds of the earth to prevent any wind from blowing on the land, or on the sea, or on any tree. Then I saw another angel coming up from the east, having the seal of the living God. He called out in a loud voice to the four angels who had been given power to harm the land and the sea: "Do not harm the land or the sea or the trees until we put a seal on the foreheads of the servants of our God." Then I heard the number of those who were sealed: 144,000 from all the tribes of Israel:
The listing clearly refers to the descendants of the The Tribes Of Israel, with a very curious omission - the tribe of Dan is not there. As with so many other things, there has been much written about why Dan was left out , the most often explanation being that they, collectively as a nation, for whatever reason, take the side of those who are persecuting the Saints - the people of God.
Although the 144,000 may well form the core, they will not be all of those who remain faithful and obedient to God during those very difficult times. There will be many millions of others from every nation on earth -
"After this I looked, and there before me was a great multitude that no one could count, from every nation, tribe, people and language, standing before The Throne and in front of The Lamb. They were wearing white robes and were holding palm branches in their hands. And they cried out in a loud voice, "Salvation belongs to our God, Who sits on The Throne, and to The Lamb." (Revelation 7:9-10)
There is much about end-time prophecy that, even like the very best road map, is only an outline or guide to where we are headed. Even though we know the road's eventual destination, we can't clearly identify the sights over the horizon until we get there. But when the time comes, from what we know from our prophecy "map," we will be able to quickly, and correctly, identify all of the people and places along the way.
Fact Finder: What will be the role of the original 12 apostles (with Matthias replacing Judas Iscariot) in God's Kingdom?