Revelation 16:15 “Behold, I come like a thief! Blessed is he who stays awake and keeps his clothes with him, so that he may not go naked and be shamefully exposed.”
This verse is a curiosity for several reasons. First, the verse appears to be Jesus’s own words. In Revelation 3:3 he warned the church at Sardis to wake up, otherwise he would come like a thief. Many English translations therefore put the verse in “red letters” like the letters to the seven churches.
Second, how is this verse related to the context? It interrupts the flow of thought: the nations are deceived by demons in verse 14 and assembled for battle, in verse 16 the location of the gathering of the nations is Armageddon. Because it seems like an interruption, many translations also put the verse in parenthesis (ESV, NRSV).
Third, this verse may be a hint of some editorial revisions of Revelation. David Aune suggests the verse is an interpolation, inserted into the text into the “second edition of Revelation” (2:896). In his view, a later editor added 1:3-14, the letters to the seven churches, this line and 22:5-21.
Jesus used the metaphor of a thief in the night in Matt 24:42-44 / Luke 12:39-40. Paul may allude to this teaching in 1 Thessalonians 5:2. In both cases the point of the metaphor is to encourage watchfulness. 2 Peter 3:10 also says the day of the Lord will come like a “thief in the night.” One main difference is the subject in the Gospels is the Son of Man, in Revelation the saying is in the first person, I am coming like a thief.” Unfortunately, this metaphor was co-opted as a warning to be ready for the rapture, but that was not the point of the metaphor in the New Testament. Watchfulness and readiness, yes, but because God’s great day of judgment is coming very soon, not the rapture of the church.
As part of his response to the disciples’ question about the signs of his return, Jesus says to be alert and awake, like someone who knows when a thief will break into their house. There are two main ideas in this saying. First, the disciples are to “stay awake” or “remain alert” (γρηγορέω), the first part of Revelation 16:15. Second, the disciples are to be prepared (ἕτοιμος), the second part of 16:15. Ironically, in the garden on the night to his arrest, Jesus told Peter, James and John stay alert (γρηγορέω) while he prayer (Matt 26:41 / Mark 14:34) yet they fell asleep. Perhaps it is not a coincidence a young follower of Jesus is sleeping when Jesus was arrested and “ran away naked” (Mark 14:51).
The second part of the verse is a beatitude: blessed is the one is stays away and dressed. Like the thief in the night saying, remaining awake and prepared is found in the Gospels and Paul’s letters as a warning to be prepared for the return of Christ. In Revelation 3:18 Jesus warning the Laodiceans to dress properly themselves in order to be prepared for the soon return of the Lord. They thought they were dressed in fine clothing but they actually shamefully naked. In Revelation 6:11 the souls under the altar were given white robes; in 7:9, 13 the 144,000 are also given white robes.
If they are not awake and dressed, then they are “going about naked” and their shamefulness (ἀσχημοσύνη) will be seen. Aside from the general embarrassment of being caught naked, the word refers to a shameless act or anything which leads to disgrace. In the Old Testament, “uncovering nakedness” is used in the context of God’s judgment on Babylon. Speaking to the “virgin daughter of Babylon,” the Lord says, “Your nakedness shall be uncovered, and your disgrace (ἀσχημοσύνη) shall be seen” (Isa 47:3, cf., Lam 1:8). The Lord covering one’s nakedness is a sign of his provision for his people (Ezek 16:8; Hos 2:11).
The ultimate conflict between God Almighty and the kingdom of the beast demands watchfulness and preparation. But this is not an instruction to hoard food, guns, and toilet paper out of fear of the government. For John, this is a spiritual battle. The spirit of deception has gone out into the world already (1 John 4:1-3) and demands the follower of Jesus remain awake, alert, and prepared at all times.
The metaphor of “I am coming like a thief” when it comes to His judgment is interesting. But at the same time, it is scary. Thieves break in and steal when a person is not prepared. The author is emphasizing the importance of being ready and prepared. As you shared (P.Long) there were multiple instances where even the disciples were not prepared and the worst things happened (Jesus was arrested). It motivates and encourages us as Christians to be ready. God is still gracious enough to give us time to prepare and be ready. “Behold, I am coming like a thief! Blessed is the one who stays awake, keeping his garments on, that he may not go about naked and be seen exposed (Revelations 16:14)!”