Mat 24:14 And this gospel of the kingdom shall be preached in all the world for a witness unto all nations; and then shall the end come.
Which end was Jesus speaking of?
2Th 2:1 Now we beseech you, brethren, by the coming of our Lord Jesus Christ, and by our gathering together unto him,
2Th 2:2 That ye be not soon shaken in mind, or be troubled, neither by spirit, nor by word, nor by letter as from us, as that the day of Christ is at hand.
2Th 2:3 Let no man deceive you by any means: for that day shall not come, except there come a falling away first, and that man of sin be revealed, the son of perdition;
2Th 2:4 Who opposeth and exalteth himself above all that is called God, or that is worshipped; so that he as God sitteth in the temple of God, shewing himself that he is God.
2Th 2:5 Remember ye not, that, when I was yet with you, I told you these things?
2Th 2:6 And now ye know what withholdeth that he might be revealed in his time.
2Th 2:7 For the mystery of iniquity doth already work: only he who now letteth will let, until he be taken out of the way.
2Th 2:8 And then shall that Wicked be revealed, whom the Lord shall consume with the spirit of his mouth, and shall destroy with the brightness of his coming:
2Th 2:9 Even him, whose coming is after the working of Satan with all power and signs and lying wonders,
2Th 2:10 And with all deceivableness of unrighteousness in them that perish; because they received not the love of the truth, that they might be saved.
2Th 2:11 And for this cause God shall send them strong delusion, that they should believe a lie:
2Th 2:12 That they all might be damned who believed not the truth, but had pleasure in unrighteousness.
The time that God allows the man of sin to deceive all people who do not love Him,to follow the beast kingdom,then when they take the mark of the beast,repentance,and salvation,is no longer available to them,and God can put the world down,and end this sin business on earth.
Isa 13:9 Behold, the day of the LORD cometh, cruel both with wrath and fierce anger, to lay the land desolate: and he shall destroy the sinners thereof out of it.
Isa 13:10 For the stars of heaven and the constellations thereof shall not give their light: the sun shall be darkened in his going forth, and the moon shall not cause her light to shine.
Isa 13:11 And I will punish the world for their evil, and the wicked for their iniquity; and I will cause the arrogancy of the proud to cease, and will lay low the haughtiness of the terrible.
The Gospel must first be preached in to all the world,and all nations must know of what the Gospel is all about,and that the Bible claims that there is a personal God,and that Jesus is Lord and Savior,and when all the world has heard the Gospel and knows what it is about,then God can allow the beast to rule,and cause all people who do not love Him to follow the beast kingdom,and when they do He will put them down,and they will have no excuse for all the world has heard the truth.