I don't believe this, Rev 16:15, is a reference to the 2nd coming but to the pretrib rapture. Look at Rev 3:1-3 and see that if Sardis didn't repent, Christ would come on them as a thief .. but there were still some who had not defiled their garments and who would be (IMO) raptured. Also, 2Cor 5:1-4 where he talks about desiring to be raptured rather than die "naked."
skypair
There is no word 'rapture' anywhere in God's Holy Writ. So overusing that word, just because that's often what those on the Pre-trib Rapture theory of man do, will not prove any kind of Biblical support. Apostle Paul used the Greek word harpazo for being "caught up", not rapture. and In 2 Cor.5:1-4, Paul was talking about the 1 Cor.15 event of being 'changed' at the twinkling of an eye, i.e., the resurrection. There is no pre-trib rapture idea taught in either of those two Scriptures.
The idea of the 'thief' that Jesus taught is at the end of Matthew 24.
Matt 24:42-51
42 Watch therefore: for ye know not what hour your Lord doth come.
43 But know this, that if the goodman of the house had known in what watch the thief would come, he would have watched, and would not have suffered his house to be broken up.
44 Therefore be ye also ready: for in such an hour as ye think not the Son of man cometh.
45 Who then is a faithful and wise servant, whom his lord hath made ruler over his household, to give them meat in due season?
46 Blessed is that servant, whom his lord when he cometh shall find so doing.
47 Verily I say unto you, That he shall make him ruler over all his goods.
The night was divided into separate watch periods, like 2 hours each. Our Lord Jesus compared His coming to a thief breaking in one's home. If you know in what 'watch' the thief would come, then you would not allow your home to be broken into. It's a simple analogy. Those who know what watch the thief will come are compared to His Church.
We won't know the very hour, but we can know the watch. In 1 Thess.5, Paul pointed to the watch when he told us that "the day of the Lord" will come "as a thief in the night". Apostle Peter said the same in 2 Pet.3:10.
The below verses are for those who don't watch, and don't know in what watch the thief would come:
48 But and if that evil servant shall say in his heart, My lord delayeth his coming;
49 And shall begin to smite his fellowservants, and to eat and drink with the drunken;
50 The lord of that servant shall come in a day when he looketh not for him, and in an hour that he is not aware of,
51 And shall cut him asunder, and appoint him his portion with the hypocrites: there shall be weeping and gnashing of teeth.
KJV
So when Jesus said at Rev.16:15 to His Church that He comes "as a thief", it means that His coming to gather His Church has NOT happened yet at that point on the 6th Vial.
I know the Pre-trib Rapture theory of men teaches that the Church is rapture out prior to the tribulation, and thus prior to the pouring out of the 7 vials of Rev.16. But those men are not keeping to God's Word as written.
So choose - either God's Word as written, or doctrines of men that cannot save.