Jesus wants us all to be alert and ready for his coming.  In Mark 13:32-37 he says,

³² But concerning that day or that hour, no one knows, not even the angels in heaven, nor the Son, but only the Father. ³³ Be on guard, keep awake. For you do not know when the time will come. ³⁴ It is like a man going on a journey, when he leaves home and puts his servants in charge, each with his work, and commands the doorkeeper to stay awake. ³⁵ Therefore stay awake—for you do not know when the master of the house will come, in the evening, or at midnight, or when the rooster crows, or in the morning— ³⁶ lest he come suddenly and find you asleep. ³⁷ And what I say to you I say to all: Stay awake.

Jesus draws an analogy between the kind of constant awareness and expectation he wants from us and the doorkeeper to a house.  In this case the doorkeeper’s master has gone off on a journey and may come back at any time.  When Jesus compares this to his own return, he points out that he, our master, might come at any moment, even in the middle of the night.  No one knows when he will arrive.

I happen to be an advocate of the pretribulation rapture view of Christ’s coming, which, among other things, seems to make the most sense of this passage.  Though I know plenty of wonderful Christians who disagree, I do hope they at least see the importance of our constant preparedness and sense of expectation.  For example, one of my former professors, who holds different views on end-times prophecy from me, still says in his commentary on this passage, 

The reference to all four watches, including the second and third watches when people avoided travel, underlines the fact that Jesus’ return may happen when it is least expected, and emphasizes that Jesus’ followers are always “on duty”: they must always, constantly, be alert, prepared for Jesus’ sudden, unexpected return. 

– Eckhard Schnabel, Gordon Conwell Theological Seminary *

In a day when people are not overly enthusiastic about Bible prophecy, there is a constant danger to shift toward a lack of enthusiasm.  Let’s not forget that the New Testament emphasizes that Jesus is coming soon.  Let’s be like the faithful doorkeeper in Christ’s comparison who is ready to open the door at any time, even at an unexpected moment.  In other words, at any and every time, Jesus might realistically be expected. 

No one knows when Jesus will return.  This means we should always be ready.

* Eckhard Schnabel, 2017. Mark, Tyndale New Testament Commentaries. (Downers Grove, IVP Academic), 339.