Summary: Although we do not know the precise day and hour of Christ's coming, in "Preparing for Christ's' Coming" we must be: 1) Alert (Matthew 24:37–42) and be 2) Ready (Matthew 24:43–44).
As children prepare wish lists, and adults plan Christmas get-togethers, this is an exciting time of year. Although it means extra planning and work, there is something exciting in the anticipation of Christmas. "Ready or not", Christmas celebrations are coming soon.
The familiar expression “Here I come, ready or not” could well be applied to Jesus’ second coming, because He is coming according to the sovereign plan of God, with no regard for worldwide or individual readiness. Jesus is coming when He is coming, because the when and how of His return have long since been predetermined in the sovereign wisdom of God. In response to the disciples’ question, “Tell us, when will these things be, and what will be the sign of Your coming, and of the end of the age?” (Mt. 24:3), Jesus told them of the birth pains that would immediately precede His coming (vv. 4–28), of the abomination of desolation (v 15), which would precipitate those signs, and of the supreme sign of His own appearing on the clouds of heaven (v 30). Now He gives them a partial answer to the “where” part of the question of His coming. Although there will be observable, worldwide, and unmistakable indications of His coming just before it occurs, the exact time will not be revealed in advance. Jesus says in Matthew 24:36:
Matthew 24:36 "But concerning that day and hour no one knows, not even the angels of heaven, nor the Son, but the Father only. (ESV)
Before we get into the elements of the Coming of Christ, we need to highlight what leads up to this point. The description of that day and hour plainly implies that a definite day and moment are fixed for this great appearing, but known only to God (The Pulpit Commentary: St. Matthew Vol. II. 2004 (H. D. M. Spence-Jones, Ed.) (441). Bellingham, WA: Logos Research Systems, Inc.). An important contrast exists between the (verses previous in Matthew 24) and this ...section of Matthew 24 to which we now come. It is the difference between “you know” in verse 33 and “no one knows” in verse 36. What the disciples were to know is that “when you see all these things” the end will be “near, right at the door.” “These things” refer to the terrible characteristics of their age, and ours—false messiahs, wars, earthquakes, famines, persecutions, apostasy, and false prophets. Having seen these things, we should know that the return of Jesus Christ is near, even at the door. That door could be flung open by Christ at any moment (Boice, J. M. (2001). The Gospel of Matthew (514–516). Grand Rapids, Mich.: Baker Books.)
The signs He had just been describing will be conclusive proof that His arrival is very near. Once they have begun, the general time period of His return will be known, because one of the key purposes of the signs will be to make it known. As D. A. Carson writes, “The hour remains unknown until it arrives; and then the cleavage is sudden, absolute, and irreversible.” (D. A. Carson, God with Us: Themes from Matthew (Ventura, Calif.: Regal Books, 1985), 146.)
But even during those sign-days the precise day and hour of Jesus’ appearing will not be known, a truth He reiterates several times in this Olivet discourse (Mt. 24:42, 44, 50; 25:13).“Day” and “hour” are regularly used throughout Scripture for “time” in general, not just twenty-four-hour or sixty-minute periods (in Matt cf. 7:22; 10:19; 24:42, 44, 50; 25:13; 26:45). “Day” especially reflects the Old Testament “Day of the Lord” (cf. esp. throughout Zephaniah) as a stock phrase for the end of the age (cf. Matthew’s “day of judgment” in 10:15; 11:22, 24; 12:36; and cf. also Rom 10:21; 1 Cor 4:5; 2 Cor 3:14; Eph 6:13) Those who claim they can narrow down the time of Christ’s return to a generation or a year or even a few day’s period, while still not knowing the literal day or hour, remain singularly ill-informed.(Blomberg, C. (2001). Vol. 22: Matthew (electronic ed.). Logos Library System; The New American Commentary (365). Nashville: Broadman & Holman Publishers.).
The supernatural world does not know the precise time of Christ's return, not even the angels of heaven. The angels, though standing in a very close relationship to God (Isa. 6:1–3; Matt. 18:10), and though intimately associated with the events pertaining to the second coming (13:41; 24:31; Rev. 14:19), do not know the day nor the hour. The angels will be directly and actively involved in the end time as God’s agents to separate the saved from the unsaved (see Matt. 13:41, 49), but for His own reasons God the Father will not reveal in advance exactly when He will call them into that service. (Hendriksen, W., & Kistemaker, S. J. (1953-2001). Vol. 9: New Testament commentary: Exposition of the Gospel According to Matthew. New Testament Commentary (869). Grand Rapids: Baker Book House.).