Revelation 19:21

And the remnant were slain with the sword of Him that sat upon the horse, which sword proceeded out of His mouth; and all the fowls were filled with their flesh.

This scene is introduced with a terrible and terrifying announcement: And I saw a single angel standing in the sun, and he called with a loud voice, saying to all the birds that fly in mid-heaven, Come, gather yourselves to the great feast of God, that ye may eat the flesh of kings and the flesh of generals and the flesh of mighty ones and the flesh of horses, and of those that sit upon them, and the flesh of all free as well as of slaves, both small and great. This is a ghastly announcement, all the more so because of its finality. In a most commanding and conspicuous position the angel with this command is placed, in order that all hearers should realize and appreciate its importance. This surely is a contrast to the joyful marriage-feast of the Lamb; for not only will the corpses of the enemies of the Lord lie unburied, in itself one of the worst misfortunes which men knew of, but their bodies should become the prey, the food, of the birds, mainly the vultures that fly in the sky above the heads of men. The destruction of Anti-Christ and of his host is thus assured from the beginning; they will be given to the evil spirits, to the devil and his angels, to be destroyed and tormented forever.

This announcement served as a sign to the forces of evil to assemble for a last great and desperate, but futile effort to storm heaven: And I saw the beast and the kings of the earth and their hordes gathered to wage war against Him that sits upon the horse and against His army. And the beast was captured, and with him the false prophet that performed the miracles before him, by which he deceived those that had accepted the mark of the beast and those that worshiped his image; while still alive, these two were thrown into the lake of fire that burns with sulfur. This is the final overthrow of the beast, the kingdom of Anti-Christ, of his false prophet, the Popes, and of all those hat had become the servants of the beast by receiving his mark on their forehead or in their hand, that had worshiped his image by bailing the hierarchical system of the Church of Rome as an organization from God. And the leaders of the anti-Christian kingdom, the seducers of the world, the avowed and implacable enemies of the Lord and of His Gospel, were punished with eternal damnation in the lake burning with fire and brimstone. Hell itself will devour them, and they will receive the punishment which their works merited. Their lot is shared by their followers: And the rest were killed by the sword of Him that sits upon the horse, that proceeds out of His mouth, and all the birds were glutted with their flesh. A gruesome picture, well calculated to call men to repentance. For the sword of the Lord is the word: "Depart from Me, ye cursed, into everlasting fire," Matthew 25:41. As the vultures make a meal of the carcasses to which their attention is directed, so will Satan and his angels forever feed on the souls and bodies of those that dared to oppose the almighty Lord and to take the parts of Anti-Christ. That is the end of the Church of Rome, of the kingdom of Anti-Christ.

Summary

The triumph of the exalted Christ and of the elect in heaven is shown in a series of pictures giving the hymn of victory, showing the army of the Lord arrayed against the hordes of Anti-Christ, and the complete overthrow and final punishment of the Lord's enemies.