Concerning times and seasons, brothers and sisters, you have no need for anything to be written to you. For you yourselves know very well that the day of the Lord will come like a thief at night. When people are saying, "Peace and security, " then sudden disaster comes upon them, like labor pains upon a pregnant woman, and they will not escape. But you, brothers and sisters, are not in darkness, for that day to overtake you like a thief. For all of you are children of the light and children of the day. We are not of the night or of darkness. Therefore, let us not sleep as the rest do, but let us stay alert and sober (1 Thess. 5:1-6)This week St. Paul addresses, again, his main reason for writing to the Church at ancient Thessaloniki, namely assuaging their concerns that some of their number had died and the Lord had not yet returned. It is important to note that while Paul, like all early Christians, expected the Lord to return soon, he made no predictions about the exact time or day, apparently not even teaching that Jesus would come before any of the first generation of believers died. It is important, however, to recognize that Paul certainly believed the Lord would return soon and almost certainly taught the imminence of the parousia as part of his apostolic proclamation.
By writing that "the apocalypsing of Jesus Christ," to use Mangina's striking phrase from his commentary on Revelation, "will come like a thief in the night," the apostle seems to be echoing words handed down from our Lord Himself (Matt. 24:42-44). Since I am already using a quote from the twenty-fourth chapter of St. Matthew, I will note that the late-developing (i.e., unknown to Tradition) doctrine of the Rapture, in addition to arising from last Sunday's second reading, also taken from St. Paul's First Letter to the Thessalonians, stems from this chapter of Matthew, specifically verses forty and forty-one: "Two men will be out in the field; one will be taken, and one will be left. Two women will be grinding at the mill; one will be taken, and one will be left." It is sometimes amazing to me that Christians in the past often read Scripture more intelligently than many in our own day.
Paul is exhorting the saints after the manner of Jesus, "Therefore, stay awake! For you do not know on which day your Lord will come" (Matt. 24:42). We often speak in a similar manner when we say things like, "You never know, you could be run over by a bus tomorrow!" Of course, we believe in Christ's glorious return, His "apocalysing," His unveiling, but our end-time could definitely precede this cosmic event. For those who already know Jesus Christ, know who He is, who, like Peter, have had Him unveiled to them, who know Him as Messiah and Lord, will be like the five wise virgins in last week's Gospel, or the two servants who made the most of what the Master gave them. This is why Paul exhorts the Christians in Thessaloniki and, by extension, us to stay awake, stay alert, and to remain sober.