Even though I tend to think the feasting birds is meaning in the literal sense, I also accept that maybe it isn't. Either way, imagery like this wouldn't be being used if the entire planet were literally engulfed in the flames at the time.
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.
Notice the chronology here, though I realize Amils typically disregard chronology a lot of the time. They are slain first, then given to the fowls. The fowls are not the ones killing them, they are the ones eating them after they have been killed.
Matthew records Jesus say:
“For as the lightning cometh out of the east, and shineth even unto the west; so shall also the coming of the Son of man be. For wheresoever the carcase is, there will the eagles be gathered together. Immediately after the tribulation of those days shall the sun be darkened, and the moon shall not give her light, and the stars shall fall from heaven, and the powers of the heavens shall be shaken: And then shall appear the sign of the Son of man in heaven: and then shall all the tribes of the earth mourn, and they shall see the Son of man coming in the clouds of heaven with power and great glory.”
Where ever the carcass is there the eagles will be gathered together. Eagles flock to where there is prey. Where bodies lie that is where they will congregate. Death and destruction mark the aftermath of God’s judgment. Whilst God’s people are rescued the wicked perish in destruction.
The parallel passage in Luke 17:24-37 tells us:
“For as the lightning, that lighteneth out of the one part under heaven, shineth unto the other part under heaven; so shall also the Son of man be in his day. But first must he suffer many things, and be rejected of this generation. And as it was in the days of Noe, so shall it be also in the days of the Son of man. They did eat, they drank, they married wives, they were given in marriage, until the day that Noe entered into the ark, and the flood came, and destroyed them all. Likewise also as it was in the days of Lot; they did eat, they drank, they bought, they sold, they planted, they builded; But the same day that Lot went out of Sodom it rained fire and brimstone from heaven, and destroyed them all. Even thus shall it be in the day when the Son of man is revealed. In that day, he which shall be upon the housetop, and his stuff in the house, let him not come down to take it away: and he that is in the field, let him likewise not return back. Remember Lot's wife. Whosoever shall seek to save his life shall lose it; and whosoever shall lose his life shall preserve it. I tell you, in that night there shall be two men in one bed; the one shall be taken, and the other shall be left. Two women shall be grinding together; the one shall be taken, and the other left. Two men shall be in the field; the one shall be taken, and the other left. And they answered and said unto him, Where, Lord? And he said unto them, Wheresoever the body is, thither will the eagles be gathered together.”
This is saying the exact same as Matthew 24. Revelation 19 also correlates with this. The eagles devour those left behind after the catching away. The disciples then ask:
“Where, Lord?” Christ replies:
“Wheresoever the body is, thither will the eagles be gathered together.” Eagles flock to where there is prey. Where bodies lie that is where they will congregate. Death and destruction mark the aftermath of God’s judgment. Whilst God’s people are rescued the wicked perish in destruction.
Significantly, the word for eagles (aetoi) is interestingly interpreted “angel” in Revelation 8:13. It reads:
"And I beheld, and heard an angel (aetos) flying through the midst of heaven, saying with a loud voice, Woe, woe, woe, to the inhabiters of the earth by reason of the other voices of the trumpet of the three angels (aggelos), which are yet to sound!"
The fowls or birds seem to be a poignant symbol of the angels of God whose job it is to exercise un-merciless judgment on the wicked on that day. Describing the nature and character of the eagle, Job 39:30 poignantly declares,
“where the slain are, there is she.” There seems good reason to believe that these fowls or birds are symbolic of the angels, which mete out justice upon the wicked on behalf of God destruction at the end of this age. They are clearly a heavenly host as, when they are bidden, they are found flying “in the midst of heaven.” Here we see the final destruction of the wicked.
Interestingly, just as God’s angels are symbolically described as birds in Revelation, so are Satan’s daemonic angels.
In Revelation 18:2 we have an interesting contrast, again fitting in with the symbolic location of these passages:
“And he cried mightily with a strong voice, saying, Babylon the great is fallen, is fallen, and is become the habitation of devils, and the hold of every foul spirit, and a cage of every unclean and hateful bird.”
The terms devils and foul spirits (namely fallen angels) are directly linked to unclean and hateful birds in this passage. Obviously, this is not speaking about literal birds. The idea of angels (or fallen angels) being called birds in Revelation is not unique.
Jesus describes demons as being like the fowls of the air in Mark 4:4 & 15 in the parable of the sower. Our Lord teaches:
“as he sowed, some fell by the way side, and the fowls of the air came and devoured it up … And these are they by the way side, where the word is sown; but when they have heard, Satan cometh immediately, and taketh away the word that was sown in their hearts.”
Every time the Gospel is faithfully preached Satan is waiting in the wings to steal that Word so that you do not apply it to your heart and it perfect. Every truth is dangerous to him because it encourages the Saints, exalts Christ and exposes him.
Revelation 19:17-18 outlines a detailed account of the assignment given to “the fowls that fly in the midst of heaven” by the heavenly messenger. The “fowls” are instructed to “come and gather” themselves “together unto the supper of the great God” in order that they would “eat”:
1. The flesh of kings,
2. The flesh of captains,
3. The flesh of mighty men,
4. The flesh of horses, them that sit on them,
5. The flesh of all men, both free and bond, both small and great.”
Revelation 19, like every other Scripture, supports a climactic coming (including the destruction of all the wicked), and in doing so reinforces the Amillennial position. Premils have to explain away the literal detail in order to facilitate Premil.
Also, they depend wholly on one flawed opinion, which if taken away, decimates the belief, that of Rev 20 being chronological with Rev 19. Take that away and it falls like a deck of cards.
Those of us who were Premil could not fight with Scripture any more, we had to impress the climactic nature of Christ's return. No wicked survive it. Sin, sinners, corruption and decay, crying and dying are banished from the new earth.