When we read this passage we can get a little confused; was the passage written after the destruction of Jerusalem? Did Jesus really say these words or were they made up by Luke to show that Jesus knew everything?
If we look at the passage like this perhaps we are coming at it from the wrong way. maybe we should apply it to ourselves. Lets looks at it another way.
Jerusalem is the the city of our life, the city of peace the way we want it to be. When tragedy strikes and disaster happens, then we are laid bare, we are surrounded by so many enemies of fear, anger, despair; "great misery will descend on the land and on this people."
Our city will be burnt down, our streets trampled and in the midst of this we shall be terrified and feel utterly lost. we will be mystified and full of fear as we watch our friends die over the years. At times our world will seem lost.
"And then you will see the Son of Man coming with power and great glory." When we are at our weakest the Lord comes to us, he never lets us down.
This is not a reading of despair but of great hope. Let's see it as such!