"Beware that your hearts do not become drowsy from carousing and drunkenness and the anxieties of daily life, and that day catch you by surprise like a trap. For that day will assault everyone who lives on the face of the earth. Be vigilant at all times and pray that you have the strength to escape the tribulations that are imminent and to stand before the Son of Man." (Lk 21:34-36)
The author is writing about the things that are happening in Jerusalem. Daily life itself is becoming difficult. Anxieties of the daily events are making the disciples weary and drowsy. The normal happenings of the day are making the heart of the disciples lose the strength of the spirit. All these are leading them to discouragement.
Anxieties, worries and all the rest of it will happen to every one. No person will be able to avoid this. All these are only going to lead one to the day. That day, the last day also will happen to everyone on the face of the earth. No one should think that he can escape this. It will happen to all and it will not be or should not be a surprise to anyone.
The teachings of Jesus for his disciples are very clear: keep alert; patience; pray for strength to keep on going. Things happen regularly and repeatedly. Anxieties and worries and destruction are part of daily happenings and they are repeated week after week and so on. What counts is patience and patience is the fruit of the spirit.