Gospel (Mt 24:37-44)
As were the days of Noah, so will be the coming of the Son of man. For as in those days before the flood they were eating and drinking, marrying and giving in marriage, until the day when Noah entered the ark, and they did not know until the flood came and swept them all away, so will be the coming of the Son of man. Then two men will be in the field; one is taken and one is left. Two women will be grinding at the mill; one is taken and one is left.
Watch therefore, for you do not know on what day your Lord is coming. But know this, that if the householder had known in what part of the night the thief was coming, he would have watched and would not have let his house be broken into. Therefore you also must be ready; for the Son of man is coming at an hour you do not expect.
Today we begin the season of Advent, a time of preparation for the coming of our Lord. The first coming took place at the Incarnation and the birth of Jesus in Bethlehem, and continued during his whole earthly life until his glorious Ascension into Heaven. But we still await a new and final visit, which is what we profess each time we recite the Creed: “He will come again in glory to judge the living and the dead.”
This Gospel passage speaks to us of that final visit of his, which will take place at the end of time. “Since the Ascension Christ’s coming in glory has been imminent,” the Catechism of the Catholic Church tells us, “even though ‘it is not for you to know times or seasons which the Father has fixed by his own authority’ (Acts 1:7). This eschatological coming could be accomplished at any moment.”
Whence Jesus’ warning that we should always be prepared. He is not trying to frighten us, but rather to open up our life to a broader vision that shows the relative value of our daily concerns while also investing them with a decisive value. Our Lord’s coming can surprise us at any moment, suddenly, when we are busy with our daily affairs: “For as in those days before the flood they were eating and drinking, marrying and giving in marriage, until the day when Noah entered the ark, and they did not know until the flood came and swept them all away, so will be the coming of the Son of man” (vv. 38-39).
Jesus’ words are an invitation to vigilance. We know that He will come, but we do not know when, so it is good to be prepared at every moment, with our heart free, not bound by the things of this world, but rather employing them as a path of sanctification.
To call attention to the need for vigilance, Jesus sets forth a short parable that his listeners readily understand: “But know this, that if the householder had known in what part of the night the thief was coming, he would have watched and would not have let his house be broken into” (v. 43). How much more diligent should we Christians be in watching over the treasure of faith and grace that we have received! “You are a Christian,” Saint Josemaria wrote, “and, as a Christian, a child of God. So you should feel a grave responsibility for corresponding to the mercies you have received from the Lord, showing careful vigilance and loving firmness, so that nothing and nobody may disfigure the distinctive features of the Love he has imprinted on your soul.”
Saint John Paul II began his Testament (to be made publice when he died) with our Lord’s warning in today’s gospel passage: “‘Watch, therefore, for you do not know on what day your Lord is coming’ (Mt 24: 42). These words remind me of the last call that will come at whatever time the Lord desires. I want to follow Him and I want all that is part of my earthly life to prepare me for this moment. I do not know when it will come but I place this moment, like all other things, in the hands of the Mother of my Master: Totus Tuus.” If we follow his example and strive to be well prepared for this decisive moment in our life, we too can await with confidence the coming of our Lord with the same serenity and abandonment in our Lady’s hands.
 Catechism of the Catholic Church, no. 673.
 Saint Josemaria, The Forge, 416.
 Saint John Paul II, Testament, Rome, 6 March 1979.