The gospel today is not easy to interpret, but I think it is correct to say that it is and was relevant to everyone who has read it and will read it. This means that it does not just refer to events of the 1st century, such as the destruction of Jerusalem--otherwise it is not relevant to us--, nor does it only refer to the period that marks the end of the world--which means it would not have been relevant for those in the first, second, third, fourth centuries, etc. This gospel says: "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."
What is this mysterious "day" that he speaks of here? It is the "day" of eternity. Eternity is a single day that is forever; it is the "day" when eternity breaks into history and history breaks into eternity. And so, it refers to a number of things. It refers to Christmas, in which the eternal Son of God entered into history; it refers to Easter when the eternal Son of God rose from the dead, and it refers to the Parousia, the Second Coming of Christ, and of course it refers to the end of our own individual lives.
Christianity is forward looking. The Kingdom of God has been established by Christ in this world, and it began as a tiny seed, but it continues to develop and grow throughout history as individual human beings permit Christ to reign over their lives. Christ's kingdom entered this world at Christmas, when he joined a human nature to himself, that is, when he became flesh. A king is born, and if he is a king, he has a kingdom. A king also goes to war to firmly establish that kingdom, and Christ came in order to defeat in battle the one enemy that no earthly king could defeat, namely death, and the paschal mystery is that defeat (Good Friday and Easter Sunday). He entered into death in order to inject it with his divine life, and his resurrection is his victory over death. And so, Christmas looks forward towards Easter; for Christmas takes place during the darkest and coldest days of the year. We have to endure the darkness and cold of late December, as well as the cold of January and February, but light and heat always follow the darkness and cold. December 25th is precisely the day when it is possible to notice that the days are beginning to get longer, gradually getting lighter and warmer as we move towards Easter.
But just as Christmas looks towards the victory of Easter, at the same time we today look towards the victory of Christ's Second Coming, when time will come to an end and he will usher in the fullness of the kingdom of God. It's precisely that end that gives meaning to human history. If time were not to come to an end, history would have no meaning; for it is always the ending of a novel that gives the story its ultimate meaning, which is why we're anxious to get to the end when we are reading a good book. I find nothing more frustrating than those Netflix series that just continue on and on, without any hint of a resolution--I feel I'm being strung along and manipulated in order to keep me watching. If I sense that this is just an artificial prolongation, I'll stop watching. It's the end that gives meaning to all that goes before, and without an end, it is all meaningless.
The meaning of human existence is precisely that Second Coming of Christ, the day that Christ ushers in the kingdom of God in its fullness. And so, Christ commands us to be vigilant, to stay awake, to pray, to beware that our hearts do not become drowsy from being so focused on the goods of this world that we no longer look forward, that we no longer look ahead, and thus lose awareness of the shortness and brevity of our existence. Because life is short. Every day is really 24 hours closer to the grave than the day before. And when we become aware of our own death, life becomes less burdensome and more enjoyable. My final 20 years of teaching were at a high school in which the chapel was on the 2nd floor, just at the top of the main staircase, and at the bottom of the same staircase going down from the 3rd to the 2nd floor. And on both walls beside the chapel doors are the pictures of those students who died while they were students at the school. There are about 10 students there, each one looking at all of us as we climb or descend the staircase. I used to tell my students that when you see them, smiling at you from the other side, just remember that they're saying: "You might be next". I used to get quite a reaction out of my students when I said that; they are just not used to thinking about their own death; they find that repugnant.
But the irony is that when we come to terms with the fact that we are going to die, that our life here is brief and fleeting, we begin to experience a joy that we would otherwise miss. Our eyes are opened to the richness and beauty of the present moment. The result is we stop wasting our present moments. The more detached we become from the world, the more we are able to enjoy the world around us. If we covet the goods of this world, if we become anxious to acquire more and more, we lose our own peace of mind and life becomes burdensome.
So let us continue to look forward to Christ's Second Coming. We have no idea when the end of history will be, but we do know our own end is relatively near. Whatever sacrifices we make in this life for the sake of eternal life will be returned to us in the end anyways, and it will be returned one hundredfold, so there is no need to be anxious. People are anxious when they are afraid that their lives or their livelihood will be taken away. Well, the fact is we are going to lose everything we have; everything will be taken away. It has to be. We cannot rise to eternal life unless we die to this world. And the sooner we begin dying to this world in the hope of the fullness of the kingdom of God, the sooner will the joy of heaven begin now.