Who is speaking in Revelation 16:15?

What's said here includes some terminology used a few times elsewhere in Scripture.  At least once by Jesus himself.  But most importantly it is phraseology assumed to be associated with the Parusia, the "Second Coming" and the Rapture.  And therefore Post-Tribbers and others may use this as evidence that the Parusia hasn't happened yet when the 6th Bowl of God's Wrath is poured out.

"Behold, I come as a thief. Blessed is he that watcheth, and keepeth his garments, lest he walk naked, and they see his shame."

Some Bibles have put this verse in Red, but not all.  So what is the context?

Before this verse it talks about the Dragon, Beast and False Prophet using Frog like messengers to gather the Kings of the East for the coming Battle.  Then verse 16 says "And he gathered them together into a place called in the Hebrew tongue Armageddon."  It sounds like the one doing the gathering is maybe the one who said that, and that was clearly defined as what some have dubbed the "Satanic Trinity".

And don't many interpretations of Revelation presume one of these three personages is pretending to be Jesus?

But even if it is Jesus speaking, there are still a few assumptions involved.

Parusia is not the word for "come" used in the "come as a thief" verses, it's usually either Heko or Ercomai.

The only time Paul uses this kind of phrase it is of the Day of the Lord not of the Parusia/Rapture.  He used it in 1 Thessalonians 5:2-4, when he's already talked about the Rapture in the prior chapter.  Same with 2 Peter 3:10.

Also at least once I've seen this verse cited specifically as evidence there are Believers on Earth at this time.  The subject of Post Rapture believers in my model is something I will make a separate post on eventually.  But this verse I don't think proves anything one way or the other on that, even if it is Jesus who is talking, I don't see it being worded as something addressed only to Believers.  In other "come as a thief" verses the point is that it is to Unbelievers he'll be coming as a thief.

But ya know what's interesting, this is the only of these thief verses to directly lead people to think the Thief is Jesus, and only because of an assumption it's Jesus talking.   But Jesus said in John 10:7-14 that He does NOT come as a Thief to steal kill and destroy, He is the Good Shepherd and the Hireling is the Thief.  The Hireling here could be the same as the Idol Shepherd of Zechariah 11, which many have taken to be the Antichrist and I've considered could be the False Prophet.

The only time Jesus own words are cited as part of this 'He comes as a Thief at the Second Coming' theme is in Matthew 24:42-50.  It's easy to see why the Lord and the Thief are presumed to be synonymous here.  But remember this passage also gets used by Pre-Tribbers to support their imminence doctrine, even though others clearly see the moral of the story as saying the opposite.

And a core teaching of Pre-Trib is their insistence that The Antichrist doesn't appear till after The Rapture.  While we know that II Thessalonians 2 clearly teaches the opposite.

 Meanwhile to many Post-Tribbers the Rapture is the same thing as the regathering of Israel.  While a theme of my Blog has been that this very part of Revelation 16 is the Beast gathering the Lost Tribes as a counterfeit Messiah-Ben Joseph.  And the true regathering of Israel is not completed till the end of or after the Millennium.

Update August 2018: So I'd somehow completely forgotten to consider the Thief imagery being brought in the letter to Sardis. So that weakens an aspect of this argument.