Believers will be arrested and persecuted by the Jews, who will throw them in prison (12), friends and family will betray each other and some will be put to death (16), and believers will be hated by everyone (17). But don't worry. Not a single hair on your head will be hurt (even if you are killed) (18).
When you see armies around Jerusalem, then you'll know desolation is near (20). Then it's time to head for the hills. Unless you're a pregnant or nursing women, that is. (23) Then you're just fucked. Too bad for you.
God's wrath will be on everyone, with dead bodies all over the place, Jerusalem will be trodden on by Gentiles until "the times of the Gentiles be fulfilled." (24) There will be signs in the sun, moon, and stars, with lots of waves in the sea. (25)
Everyone will be afraid of everything (26) and then they'll see the Son of Man coming in all his glory. (27)
Oh, and all these things will happen within the lifespan of Jesus' contemporaries (32). 21:8-27