In some sense at least, we do not need Jesus to tell us that the world is going to be full of troubles. What we need, and what we find, is an interpretation of trouble. Providence, however dark, is always purposive. Revelation 6 provides for us a way to look at the troubles of this world and give them an explanation from a Christian and theocentric, or God-centered, point of view. Jesus, so it seems, had not taken all their troubles away.
Revelation is a glimpse at the future in order to steel the nerves of the faithful.
These were intensely personal issues for the church in John's day, but they remain problematic for Christians in every age. John's method has prepared us for the worst. After examining chapter 6 we will be all the more grateful for chapters 4 and 5. Only to the extent that we know Christ's rule shall we appreciate how he conquers every foe. There is no real break following the end of chapter 5.