The chapter basically opens up (in verse 5) with talk about the Temple and how beautiful it was. Jesus immediately says that the days are coming in which not one stone will be left on one another. We know (nowadays) that He was talking about 70 A.D. Of course, the disciples didn't know that and they were listening. He continues talking about that time of 70 A.D.
Luke Chapter 21 5 Then, as some spoke of the temple, how it was adorned with beautiful stones and donations, He said, 6 "These things which you see--the days will come in which not one stone shall be left upon another that shall not be thrown down."
So, they ask Jesus, about "not one stone shall be left upon another".... as to "when will these things be?" And now Jesus goes into it for them...
7 So they asked Him, saying, "Teacher, but when will these things be? And what sign will there be when these things are about to take place?" 8 And He said: "Take heed that you not be deceived. For many will come in My name, saying, 'I am He,' and, 'The time has drawn near.' Therefore do not go after them. 9 But when you hear of wars and commotions, do not be terrified; for these things must come to pass first, but the end will not come immediately." 10 Then He said to them, "Nation will rise against nation, and kingdom against kingdom. 11 And there will be great earthquakes in various places, and famines and pestilences; and there will be fearful sights and great signs from heaven. 12 But before all these things, they will lay their hands on you and persecute you, delivering you up to the synagogues and prisons. You will be brought before kings and rulers for My name's sake. 13 But it will turn out for you as an occasion for testimony. 14 Therefore settle it in your hearts not to meditate beforehand on what you will answer; 15 for I will give you a mouth and wisdom which all your adversaries will not be able to contradict or resist. 16 You will be betrayed even by parents and brothers, relatives and friends; and they will put some of you to death. 17 And you will be hated by all for My name's sake. 18 But not a hair of your head shall be lost. 19 By your patience possess your souls.
Now Jesus gives them a critical sign for the coming 70 A.D. destruction...
20 "But when you see Jerusalem surrounded by armies, then know that its desolation is near. 21 Then let those who are in Judea flee to the mountains, let those who are in the midst of her depart, and let not those who are in the country enter her. 22 For these are the days of vengeance, that all things which are written may be fulfilled. 23 But woe to those who are pregnant and to those who are nursing babies in those days! For there will be great distress in the land and wrath upon this people. 24 And they will fall by the edge of the sword, and be led away captive into all nations. And Jerusalem will be trampled by Gentiles until the times of the Gentiles are fulfilled.
It was right here that many Christians of that time were able to esacpe before the destruction, from Jesus' warnings. The Christians knew about this coming ahead of time, and many of them did escape beforehand. But, the Jews who were ignorant of Jesus' teachings and/or ignored them, they stayed and were killed (or many of them were killed).
Now, in verse 24, there's a "segue" involved... :-)
Jesus "transitions" from 70 A.D. -- all the way out to the end of the "times of the Gentiles". Now we're hearing about "the end" and when Jesus comes to set up the Kingdom, after the "times of the Gentiles" are completed.
25 "And there will be signs in the sun, in the moon, and in the stars; and on the earth distress of nations, with perplexity, the sea and the waves roaring; 26 men's hearts failing them from fear and the expectation of those things which are coming on the earth, for the powers of heaven will be shaken. 27 Then they will see the Son of Man coming in a cloud with power and great glory. 28 Now when these things begin to happen, look up and lift up your heads, because your redemption draws near."
Jesus goes into a parable about how to recognize the time of His coming to set up His Kingdom.
29 Then He spoke to them a parable: "Look at the fig tree, and all the trees. 30 When they are already budding, you see and know for yourselves that summer is now near. 31 So you also, when you see these things happening, know that the kingdom of God is near.
And now He makes clear that these things happening just before the time of Jesus setting up the Kingdom on this earth -- will happen in a generation. In other words, when it starts happening (at the end of the Times of the Gentiles), it will all happen quickly, during the time of just one generation.
32 Assuredly, I say to you, this generation will by no means pass away till all things take place. 33 Heaven and earth will pass away, but My words will by no means pass away.
Now Jesus comes back to the disciples who are sitting in front of him, probably shocked and spellbound and listening intently. And Jesus brings it "back to the present" where He's sitting, right now talking to them. And He says to His disciples...
34 "But take heed to yourselves, lest your hearts be weighed down with carousing, drunkenness, and cares of this life, and that Day come on you unexpectedly. 35 For it will come as a snare on all those who dwell on the face of the whole earth. 36 Watch therefore, and pray always that you may be counted worthy to escape all these things that will come to pass, and to stand before the Son of Man."
His disciples, who are sitting in front of Him, listening -- are the ones who are going to see the destruction in 70 A.D. so they need to follow Jesus' instructions regarding this.
But, in that message to His disciples, we also got a message to us, in the future, who are coming up on the end of the "Times of the Gentiles"...
So, don't confuse what is for us today and what was for the disciples who were sitting in front of Him at the time. :-)
” Now Jesus comes back to the disciples who are sitting in front of him, probably shocked and spellbound and listening intently. And Jesus brings it “back to the present” where He’s sitting, right now talking to them. And He says to His disciples...
34 “But take heed to yourselves, lest your hearts be weighed down with
carousing, drunkenness, and cares of this life, and that Day come on
you unexpectedly.
35 For it will come as a snare on all those who dwell on the face of
the whole earth.”
+++++++++++++++
Friend, consider this, what he is warning them of is an event that, “will come as a snare on all those who dwell on the face of the whole earth”
That can not describe the destruction of Jerusalem in 70 AD.
It is a world-wide catastrophe to which he is referring.