Luke's account (the temple discourse) is aimed at the gentile nations, those who will experience the roaring of the sea, etc (see earlier post luke only has sea roaring).
Matthew and Mark's account (of the Olivet discourse) is aimed at those in Jerusalem at the time of the end. They are protected by the Mediterranean from the excesses the atlantic and pacific coasts shall experience, "the roaring of the sea and the waves".
There appears, then, to be a geographic element to this. Think it through, folks, think it through. I am not absolutely saying this is the case but it is worthy of consideration.
Luk 21:36 But stay awake at all times, praying that you may have strength to escape all these things that are going to take place, and to stand before the Son of Man."Matthew paints a different picture:-
Mat 24:22 And if those days had not been cut short, no human being would be saved. But for the sake of the elect those days will be cut short.Matthew does not hold any hope of escape except the days be shortened. Luke does not mention the days being shortened but places the onus on individuals to stay awake. Those are two very different approaches to the time just before the Lord returns.
One more thing to note.
Luk 21:36 Then be watchful at every time, begging that you be counted worthy to escape all these things, the things being about to happen, and to stand before the Son of Man.Some translations have it "be counted worthy to escape" rather than "strength to escape".
Perhaps the previous verse tells us the import of verse 36
Luk 21:34 "But watch yourselves lest your hearts be weighed down with dissipation and drunkenness and cares of this life, and that day come upon you suddenly like a trap.It may be time to sober up, to really wake up. Time to get everything founded on the Rock.
It might be as simple as switching off the telly drivel and doing something useful with your time. Get your light shining because we are approaching midnight. The only mountain retreat that will save you is your feet firmly on the Rock, the Lord Jesus.
Mat 24:15 "So when you see the abomination of desolation spoken of by the prophet Daniel, standing in the holy place (let the reader understand),
Mat 24:16 then let those who are in Judea flee to the mountains.
Mat 24:17 Let the one who is on the housetop not go down to take what is in his house,
Mat 24:18 and let the one who is in the field not turn back to take his cloak.
Mat 24:19 And alas for women who are pregnant and for those who are nursing infants in those days!
Mat 24:20 Pray that your flight may not be in winter or on a Sabbath.
Mat 24:21 For then there will be great tribulation, such as has not been from the beginning of the world until now, no, and never will be.
Mat 24:22 And if those days had not been cut short, no human being would be saved. But for the sake of the elect those days will be cut short.
Mat 24:29 "Immediately after the tribulation of those days the sun will be darkened, and the moon will not give its light, and the stars will fall from heaven, and the powers of the heavens will be shaken.
Mat 24:30 Then will appear in heaven the sign of the Son of Man, and then all the tribes of the earth will mourn, and they will see the Son of Man coming on the clouds of heaven with power and great glory
Luk 21:25 "And there will be signs in sun and moon and stars, and on the earth distress of nations in perplexity because of the roaring of the sea and the waves,
Luk 21:26 people fainting with fear and with foreboding of what is coming on the world. For the powers of the heavens will be shaken.
Luk 21:27 And then they will see the Son of Man coming in a cloud with power and great glory.