An Interpretation of Matthew 24–25
Dr. Thomas Ice
"Therefore be on the alert, for you do not know which day your Lord is coming. But be sure of this, that if the head of the house had known at what time of the night the thief was coming, he would have been on the alert and would not have allowed his house to be broken into. For this reason you be ready too; for the Son of Man is coming at an hour when you do not think He will."
Three major themes are emphasized in the parables that conclude the twenty-fourth chapter of Matthew. Watchfulness was the emphasis concerning the parable of the fig tree (24:32–34). The comparison of Christ’s return to the days of Noah focuses on preparedness (24:36–41). The section I am now entering (24:42–51) provides two parables that teach lessons of faithfulness in service to our Lord. The first parable in this section is found in verses 42–44. Mark’s account of the Olivet Discourse does not have this identical parable, but Luke does in a different context (12:39–40).
This parable tells us about an owner of a house that has received a warning that a thief was coming to break into his house. Since he knows the time in which the thief was to arrive, the responsible owner prepares for this impending event by setting a watch to guard the house and protect it from a possible break-in. The point of the lesson is that if one knows the time and place of when something will occur, then the responsible thing to do would be to take conscientious action in light of the impending event.
Be on the Alert
Following on the heels of the "one taken and the other left" passages, Jesus concludes that one needs to be alert concerning His coming. This verse (42) provides a hinge between the preceding context advocating preparedness and the following context that emphasizes alertness concerning that day. "This exhortation is the chief exhortation of a parenthetical section of parables," notes James Gray. "It is the result of the preceding parable (indicated by the word ’therefore’), and an incentive or bridge for the parables that illustrate the need for such watchfulness." 
The Greek verb gregoreo is translated "alert" in this passage and is used 22 times in the Greek New Testament. It has the idea of "to stay awake, be watchful"  in some passages. This word is used of Christ’s appeal to his sleepy disciples as He prayed in the Garden of Gethsemane shortly before His crucifixion (Matt. 26:38, 40, 41; Mark 14:34, 37, 38). It is also used in this way i n the next verse of this passage (Matt. 24:43). However, the majority of its uses have the nuance of "to be in constant readiness" and to "be on the alert,"  which is how it is used here in Matthew 24:42. "The phrase be on the alert translates a present imperative, indicating a call for continual expectancy,"  observes John MacArthur.
Rapture or Second Coming?
Some argue that since one is told to be on the alert, this passage and surrounding context do not speak concerning the second coming, but the rapture instead. Dave Hunt says the following:
When Christ says, "As it was in the days of Noah and Lot," it is absolutely certain that He is not describing conditions that will prevail at the time of the Second Coming. Therefore, these must be the conditions which will prevail just prior to the Rapture at a different time–and, obviously, before the devastation of the tribulation period.
Of course, I certainly believe in the pre-trib rapture, but do not believe that is what Christ had in mind in this passage.
I contend that even though one passes through the momentous events of the tribulation, Scripture teaches that unbelievers will not be alert to the coming of Christ because of their deadness to the things of God. Consider two other important passages that use the Greek word for alert: First, look at Paul’s teaching in 1 Thessalonians 5 about how believers and unbelievers relate to the coming tribulation period. Paul tells us that unbelievers will be seeking peace and safety at this time, but "then destruction will come upon them suddenly like birth pangs upon a woman with child; and they shall not escape" (5:3). In contrast to this believers "are not in darkness, that the day should overtake you like a thief" (5:4). The explanation given by Paul as to why believers will not be surprised is because "you are all sons of light and sons of day" (5:5). Following the rational that Paul has provided thus far, he says, "so then let us not sleep as others do, but let us be alert and sober" (5:6). Here is the word "alert" that is used by our Lord in Matthew 24, which is employed in a similar way by Paul to denote constant readiness or alert in relation to "the day of the Lord," since we are children of the day. The point is that unbelievers (children of darkness) are not alert and are asleep to the things of God. They are caught off guard by virtue of the fact that they are unbelievers. Because of their unbelief they are not prepared.
A second significant use of the word "alert" is found in Revelation 16:15, which says, "(‘Behold, I am coming like a thief. Blessed is the one who stays awake and keeps his garments, lest he walk about naked and men see his shame.’)" This is translated as a parenthetical statement at the end of the sixth bowl judgment. Using the logic of those who say that "coming like a thief" would not catch unbelievers off guard does not account for this passage. Here we have seen 18 of the 19 major judgments of the tribulation and the earth is just about destroyed along with over half of the world’s population and there is issued a warning about being alert. Yes, because unbelievers a re never alert to what God is doing. That is the point! Not whether the world is experiencing a time of disruption, but whether one is listening to God’s Word and is prepared. Believers, at this time will be alert, while unbelievers, as always, will not be.
The Jewish Remnant
The meaning of this parable is clear and understandable. Believers will be watching because they know that a thief is coming during this time. Thus, they are prepared and alert. Christ presents the punch line of the parable in verse 44 when He says, "For this reason (as stated in the two previous verses), you be ready too." To whom does the "you" reference? I believe it refers to the Jewish remnant. Jesus has been using the "you" throughout the Olivet Discourse as a reference to the Jewish people. Since He clearly has in mind believers in verse 44, since only believers will be alert, then this passage refers specifically to the Jewish remnant during the tribulation. "This warning will be understood and heeded by the Jewish remnant, to which it is addressed," declares Arno Gaebelein. "They are to watch for the Son of Man; the church is to wait for her Lord." 
Israel was not prepared and ready when Christ came the first time, but the remnant will be prepared and ready when He arrives the second time. That the Jewish remnant is in view here is further supported by the observation that all of the parables that Christ speaks relate to Israel and their response to Messiah. MacArthur notes: "In this context, being ready seems to refer primarily to being saved, of being spiritually prepared to meet Christ as Lord and King rather than Judge."  Thus, our Lord is letting Israel know that they need to be prepared for His return, whenever that it. Preparation is made when one trusts Jesus as their Messiah. Stanley Toussaint concludes: "The lesson is evident. When the householder knows the general time in which the thief should come, he prepares himself accordingly. ’For this reason" the believers of the age of the tribulation should be prepared. The signs of the end will equip them to know generally or ‘in which watch’ the Son of Man should come." 
The parables in this section, prepares the way for the parables lessons in Matthew 25. Randolph Yeager has summarized this section as follows:
The entire passage in context from verse 36 teaches that (1) in Jesus’ day, no one knew the date of the advent except the Father, (2) that Noah’s days were analogous to the last days; (3) that the unsaved in Noah’s day did not know when the flood would come; (4) but that the saved (Noah and his family) did know at least seven days in advance; (5) further, that since, when the Lord comes, He will divide between the saints and sinners, (6) we ought to be watching the signs of the times for hints that will tell us when He will come, inasmuch as (7) we do not now have such information.
 James R. Gray, Prophecy on The Mount: A Dispensational Study of the Olivet Discourse (Chandler, AZ: Berean Advocate Ministries, 1991), p. 101.
 Walter Bauer, William F. Arndt, and F. Wilbur Gingrich, A Greek-English Lexicon of the New Testament and Other Early Christian Literature, 3d ed., rev. Frederick W. Danker (Chicago: University of Chicago Press, 2000), p. 209.
 BDAG, p. 209.
 John MacArthur, Matthew 24–28, The MacArthur New Testament Commentary (Chicago: Moody, 1989), p. 75.
 Dave Hunt, How Close Are We? Compelling Evidence for the Soon Return of Christ (Eugene, OR: Harvest House, 1993), pp. 210–11.
 Arno C. Gaebelein, The Gospel of Matthew: An Exposition (Neptune, NJ: Loizeaux Brothers,  1961), p. 516. (emphasis original)
 MacArthur, Matthew 24–28, p. 77.
 Stanley D. Toussaint, Behold The King: A Study of Matthew (Portland: Multnomah Press, 1980), p. 282.
 Randolph O. Yeager, The Renaissance New Testament, 18 vols. (Bowling Green, KY: Renaissance Press, 1978), vol. 3. p. 335.