20a“But when you see Jerusalem surrounded by armies, then know that its desolation is near.
21Then 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.
Articles, Bible studies, and sermons that contain Luke 21:17:
Luke 21:12-19
It's obvious from verse 18 that he's not saying that these people will absolutely not die. Some of them indeed are going to die. When this is combined with Revelation 6:9-11, it shows that some—who were certainly not by any appearance at all Laodicean—are going to lose their lives as martyrs, as witnesses for God in the coming tribulation.