Luke 21 needs to be untangled from ideas about end times, the rapture, and apocolypse before we can see it for what it is. When we do, we find Jesus describing the iminent hard times ahead and giving words of courage, hope, and comfort to his disciples.
The message is this:
Take courage. Don’t lose heart. Hold your head up high. Stay engaged with me. It might suck, but my presence and care won’t abandon you; I’ll walk you to the light at the end of the tunnel.