If He's talking to His disciples and warning them about it in the context of talking about tribulation leading up to the coming of the Son of man, is it the world's tribulation or the elect's tribulation He's warning the elect about?
Did the disciples remain alive until the Second Coming?
Did those disciples choose Christ, or did Christ choose them?
The elect are all those written in the Lamb's book of life. Once removed from the Lamb's book of life they are no longer the elect.
The church is removed from the earth at the Second Coming. But that is not the end. After the Second Coming, there is the time of Jacob's trouble. That is when Jesus and the angels gather the final harvest. The 144k are the sealed firstfruits of the restored Israelite Nation. So there are elect on earth not part of the church, and not even part of Israel, after the Second Coming. They are elect, until they are removed from the Lamb's book of life. They are to flee from Satan and company to make a rational decision. But during the GT and final harvest, it is Jesus who decides who receives eternal life and who receives eternal damnation.
The choice to accept God is not available while Jesus is on the earth. During the last 42 months, when Satan is given the throne, the choice is available. But the choice is between chopping off one's head or taking the mark.
Jesus is warning all on earth, even the elect who are not part of the church. You don't seem to accept election is universal. That does not mean every one will be redeemed. The elect just means that every one ever conceived had an opportunity to accept God. God did not condemn some to death. Many claim God condemned Esau to death, because He loved Jacob, but hated Esau. Jacob and Esau are just examples of those who accept God and those who keep rejecting every opportunity God gives them. God also hates lukewarm believers.
"I know thy works, that thou art neither cold nor hot: I would thou wert cold or hot. So then because thou art lukewarm, and neither cold nor hot, I will spue thee out of my mouth."
So the point about Jacob's trouble is that all humanity left on earth go through this time, and there are elect still on earth. Elect does not mean you are part of the NT Covenant. The disciples were chosen, redeemed, and elect. Then Judas decided to reject God. That was his choice. Until his name is removed from the Lamb's book of life, he is still elected by God. The church are those who act on the election and receive the second birth. For the 11 disciples that was the day of Pentecost. So they were elect and chosen prior to the second birth.
So was the Olivet Discourse to the church, the elect, or the redeemed? Do parts of it apply to the elect, to the church, or to the redeemed? The millions killed in 70AD were elect. They still physically died outside of the second birth. A soul is elect until removed from the Lamb's book of life.
God is not willing that any should perish, but that all come to repentance.
Can the dead come to repentance at the GWT in Revelation 20:12?
"And I saw the dead, small and great, stand before God; and the books were opened: and another book was opened, which is the book of life: and the dead were judged out of those things which were written in the books, according to their works."
If the Lamb's book of life is opened, that would be the time many dead would be removed. I mean, many Amil believe that is when both the redeemed and lost are resurrected and separated, no? Even Daniel was told that many would receive eternal life at that point. So even in death, some elect are still considered the dead.
If you are one who thinks the elect are only a few percent of all humanity, then you are wrong in thinking that. Those disciples on the mount of Olives were redeemed and elect, but also the firstfruits of the NT Covenant and not even a part of the church until the day of Pentecost. No verse claims the original 12 disciples were sealed and unable to reject Jesus Christ. However, the 144k are sealed and separated from the church, because they were still on earth after the Second Coming. They are elect because they are in the Lamb's book of life. They are sealed and remain in the Lamb's book of life. Then the 7th Seal is opened and they are on earth with Jesus as their King during the Trumpets and Thunders. They are the firstfruits of the Millennial Kingdom.
The church is all the redeemed in Paradise both OT and NT souls. There will be sealed and redeemed humans on earth during the Millennium. Those born in the Millennium are not lost people. They are not in Adam's dead image. They do not even need redemption, because they are not born in sin. But that seems to be lost on modern day theology and eschatology. Those souls currently in sheol do not need redemption. They already have that available. They cannot experience anything but punishment. They cannot change their condition by choice. What they did in their lifetime on earth is already recorded and is what holds them accountable.
Those currently in Paradise cannot choose to sin, nor live in rebellion to God. So what is the issue about the Millennium where sin is removed and there is eternal righteousness? On earth will be the only place where one can choose to disobey. But that means eternal death and separation from God, and they were not in the Lamb's book of life, because they were not in Adam's dead corruptible flesh and in need of redemption. That is also what people forget about pre-flood earth. There were sons of God living on the earth, not in Adam's dead corruptible flesh, so not in need of redemption. But when they started to have offspring with Adam's dead corruptible flesh, that offspring became sinners, and that offspring had offspring that became even more wicked, generation after generation.
Good fruit cannot change bad fruit. It is the bad fruit that corrupts all the good fruit. So the sons of God were removed from the earth. Just like the church will be removed prior to the final harvest. The 144k are sealed and like Noah in the ark go through the Trumpets and Thunders. In fact at the Second Coming, those of the second birth are all made sons of God. Now they are as all the Sons of God created on day six, and multiplied and filled the earth prior to the Flood. Adam's offspring restored to the full image of God. Those on earth still only have a soul and body. But those born during the Millennium are not written into the Lamb's book of life. They never die, so never need redeemed. Unlike Adam no human will bring sin into the world, and death by sin.