This invisible coming of the Lord to cleanse His church is so prominent on the Lord’s agenda, He waste no time to convey this message to many of His prophets. Isaiah 66 expresses this “Refiner’s Fire” as follows:
“For, behold, the LORD will come with fire, and with his chariots like a whirlwind, to render his anger with fury, and his rebuke with flames of fire. For by fire and by his sword will the LORD plead with all flesh: and the slain of the LORD shall be many. They that sanctify themselves, and purify themselves in the gardens behind one [tree] in the midst, eating swine’s flesh, and the abomination, and the mouse, shall be consumed together, saith the LORD. For I [know] their works and their thoughts: it shall come, that I will gather all nations and tongues; and they shall come, and see my glory. And I will set a sign among them, and I will send those that escape of them unto the nations, [to] Tarshish, Pul, and Lud, that draw the bow, [to] Tubal, and Javan, [to] the isles afar off, that have not heard my fame, neither have seen my glory; and they shall declare my glory among the Gentiles. And they shall bring all your brethren [for] an offering unto the LORD out of all nations upon horses, and in chariots, and in litters, and upon mules, and upon swift beasts, to my holy mountain Jerusalem, saith the LORD, as the children of Israel bring an offering in a clean vessel into the house of the LORD.” Isaiah 66:15-20.
This coming of the Lord is not His second advent, because at that time He comes to plead with no one. At this coming many will be slain but not by His brightness, according to 1 Thessalonians 4:16, 17. We notice that those (the 144,000) who escape the purifying fire are then sent as missionaries to the nations to declare His glory and to gather all their brethren – the second fruits from all nations, the other sheep that were not of this fold.