Jesus' list of complaints about the Pharisees and prophets: hypocrites, lazy, ostentatious, lovers of fine clothing. Also, they like to be called Father or Rabbi in the public square, and only god should be called either of those. Now I wonder if there are super Christians out there who call their dads something else. But they'll get theirs in the end. Then there's a lot of ranting about swearing and temples and damning to hell.
Jesus starts describing the end of the world in visceral detail. First, lots of people will claim to be Christ. Then there will be all the usual things: wars, pestilence, plague, famine. But those will only be the beginning! Believers will be tortured by non-believers, until they start to turn on each other. False prophets will promote sin and kill love. But! People who manage to endure all this will get to heaven.
When the apocalypse starts, run for the hills. But only the able-bodied young men, because woe unto them that are with child, and to them that give suck in those days! (v. 19) The Christian apologists are all like, 'Well, duh, it's a siege! Of course the women won't be able to run as fast as the able-bodied men! What do you expect?' These constant reminders of how much the bible just loves fetuses and little babies just warm my heart to its very cockles. Also, hope it doesn't happen in winter or on a Sabbath, because as we all remember, long journeys are prohibited then.
Other signs of the end of the world: no more sun or moon, the stars will fall out of the sky. Eventually, though, his sign will appear in the sky and some angels will swoop down and take the chosen people to heaven. All this will happen within the disciples' lifetimes. Jerry Falwell's bible experiences a system overload at this verse and comes up with: the previously lifted signs wil continue to multiply throughout the church age and reach their ultimate climax at the end of the age in the generation of those who will live to see the entire mater fulfilled in their lifetime. In other words: don't think to hard, kids.
We won't know when any of this is coming, one day you'll be tilling the fields with your friend, and he'll just... disappear into thin air. So be watchful.