The fact is that one day ALL will come to know God. It's prophecy. The first fruits(throughout history, King David, Moses, Sampson... all will be there) will be the first to resurrected, being caught up in heaven as our Lord comes back again. 144,000
This is for this "age," there are different "ages" and "ages to come."
If God wants to "save" everybody, do you believe He's not able? Do you believe he DOESN'T want to save everybody?
Whether or not this belief is considered "Universalism" or whatever 'isms that may apply, this is what I have gathered from my studies.