Jesus has warned His disciples that because they do not know the day or hour their Lord is coming they need to be on the alert. In a spiritual sense this means to be filled with the Holy Spirit of God in order to be of sober spirit for the purpose of prayer, rather than being filled with the spirit of the world which like wine or liquor makes one spiritually drunk and incapable of keeping watch. What illustration does Jesus now give to illustrate their need to keep on the alert? See Mat 24:43.
Notice that “what time of the night” is literally “in what watch” as in the KJV. How many watches of the night were there, and when were they? See Mar 6:48, 13:35. Why is there typically no need for watches during the day? Think: is the danger as great when the light is shining brightly and most people are awake? What does this remind us about the heightened danger in times of darkness and hence the greater need to be alert and keep watch? Why was the night divided into four watches instead of just one? Think: since it is natural for people to sleep at night, what is the danger of relying upon a single watch to remain awake and alert for the entire night? What does this again remind us about the much greater danger at night when darkness surrounds? What does a time of spiritual darkness look like in which it is especially important to keep watch, and in what sense are people asleep? See Mat 24:37-39. Among the apostles, prophets, evangelists, and pastor-teachers whom the Lord has given for works of service in the church (Eph 4:11), which are the watchmen, especially in times of darkness when others have fallen asleep? See Eze 33:2-9. How does this help us to understand who the porter or doorkeeper represents in Jesus’ parables? See Mar 13:34, Joh 10:3. In what sense was John the Baptist both a watchman and a doorkeeper in opening the door to the Good Shepherd so that the sheep of His flock would go out after Him? See Mat 11:9-14, 21:32, Luk 3:10-14, Joh 1:32-34, 5:33.
What is the great danger to a community if those who are responsible to keep watch fall asleep or are not completely sober in order to be alert and warn others when danger threatens? Are we being diligent to keep watch, or are we falling asleep in a drunken stupor having imbibed of the spirit of the world? What is the great danger to souls if when warned by God’s prophets who are awake and alert, rather than giving heed to the danger they ignore the danger or try to silence the watchman because they don’t want their sleep to be disturbed? Cf. Mat 23:34-35 and consider: In how much more danger does a person put himself by covering his head with a pillow when the fire alarm goes off, or by disconnecting the check engine light on a car rather than investigating what might be wrong? What does this remind us about the importance of every gifting among God’s people—even God’s prophets who are like a siren and may seem to be annoying?
Observe that Jesus often used “the head of the house” in His parables, and the Greek word used is variously translated as goodman, householder, landowner, or master of the house. To whom does “the head of the house” refer in those parables? See Mat 10:25, 13:27,52, 20:1,11, 21:33, Luk 13:25, 14:21. Who then might we understand the head of the house to be in the parable in Mat 24:43, and what is His house? See Heb 3:6. Does even the head of the house know at what time of night the thief is coming? See Mat 24:36. Even if the head of the house had known at what time of the night the thief was coming, what does Jesus say he would have done? But since even the head of the house does not know at what time of the night the thief is coming—only that he is coming—how important is it even for the head of the house to keep watch? Cf. Mat 26:36-46. How much more important is it for the slaves of the house to keep watch and be ready when evil threatens and they are tempted by the spirit of the world and its false messiahs to overcome evil with evil so as also to be swept away in the flood of evil? See Mat 24:44 and notice that you there is emphatic in the Greek; i.e., “you also must be ready”; contrast Mat 26:51-52; cf. 1Co 16:13-14, Rom 12:21. How especially important is it for the faithful and sensible slaves or stewards whom the master puts in charge of his house to keep watch? See Mat 24:45-51, Luk 12:35-48; cf. Act 20:31.