The Devil is the flesh and the world the flesh experiences. During the time that each saint is testifying to the word of the Lord, the flesh of the saint is kept from most sinning so this is why God makes them eunuchs until He is done using the saint. Then the flesh of the saint is killed by the religious heathens who think their interpretations of what they read in the Bible are true.
Revelation 6
9: When he opened the fifth seal, I saw under the altar the souls of those who had been slain for the word of God and for the witness they had borne;
10: they cried out with a loud voice, "O Sovereign Lord, holy and true, how long before thou wilt judge and avenge our blood on those who dwell upon the earth?"
11: Then they were each given a white robe and told to rest a little longer, until the number of their fellow servants and their brethren should be complete, who were to be killed as they themselves had been.
The last saint is writing this post and when he is killed, the 1,000 year reign of Christ will end. Then this age will end with a catastrophic ending as the earth begins to shake violently.
Isaiah 24
18: He who flees at the sound of the terror shall fall into the pit; and he who climbs out of the pit shall be caught in the snare. For the windows of heaven are opened, and the foundations of the earth tremble.
19: The earth is utterly broken, the earth is rent asunder, the earth is violently shaken.
20: The earth staggers like a drunken man, it sways like a hut; its transgression lies heavy upon it, and it falls, and will not rise again.
The end is near.
Zephaniah 1
18: Neither their silver nor their gold shall be able to deliver them on the day of the wrath of the LORD. In the fire of his jealous wrath, all the earth shall be consumed; for a full, yea, sudden end he will make of all the inhabitants of the earth.
2 Peter 3
10: But the day of the Lord will come like a thief, and then the heavens will pass away with a loud noise, and the elements will be dissolved with fire, and the earth and the works that are upon it will be burned up.
11: Since all these things are thus to be dissolved, what sort of persons ought you to be in lives of holiness and godliness,
12: waiting for and hastening the coming of the day of God, because of which the heavens will be kindled and dissolved, and the elements will melt with fire!
13: But according to his promise we wait for new heavens and a new earth in which righteousness dwells.
Ecclesiastes 1
4: A generation goes, and a generation comes, but the earth remains for ever.