The plagues in Revelation are indeed literal plagues. This is proven simply by looking at the description of some of the plagues and the words of Jesus Christ himself, whose words prove that the plagues must be literal. Let's look at the evidence:
"21For then shall be great tribulation, such as was not since the beginning of the world to this time, no, nor ever shall be. 22And except those days should be shortened, there should no flesh be saved: but for the elect's sake those days shall be shortened." Mt. 24:21-22
These verses alone (and there are more) prove that the plagues in the book of Revelation must be mostly literal. This time of tribulation in the book of Revelation must be even greater than the Holocaust, greater than anything Mao or Stalin did, greater than any war that was ever fought. Indeed, so great is the tribulation that unless those days were shortened (and I believe it is a literal shortening of the 24 hour day) everyone would die. But there is even more evidence that the plagues are literal in the book of Daniel:
"1And at that time shall Michael stand up, the great prince which standeth for the children of thy people: and there shall be a time of trouble, such as never was since there was a nation even to that same time: and at that time thy people shall be delivered, every one that shall be found written in the book. " Dan. 12:1
This must be what Christ is referring to in Mt. 24. Yet there is even more evidence:
"25And there shall be signs in the sun, and in the moon, and in the stars; and upon the earth distress of nations, with perplexity; the sea and the waves roaring; 26Men's hearts failing them for fear, and for looking after those things which are coming on the earth: for the powers of heaven shall be shaken." Lu. 21:25-26
This verse plainly proves the events in Revelation are not symbolic at all, but are literal. The nations are distressed and "perplexed." It is interesting to study the word "perplexed" in Greek:
Perplexity, #640, aporia, (Thayer) the state of one who is in perplexity. Vine's: "akin to A, No. 1, is translated "perplexity" in Luk 21:25 (lit., "at a loss for a way," a, negative, poros, "a way, resource"), of the distress of nations, finding no solution to their embarrassments; papyri illustrations are in the sense of being at one's wit's end, at a loss how to proceed, without resources."
Obviously they are "at a loss for a way" because of the terrible things that are happening to the planet. The other words are also useful to study: Distress, #4928, synoche, (Thayer)
1) a holding together, a narrowing
2) the contracting part of a way
3) metaph. straits, distress, anguish
Looking after, #4329, prosdokia, (Thayer) 1) expectation (whether good or evil).
So great and terrible will be the events happening to the earth that people will actually die of heart attacks (men's hearts failing them for fear). What could possibly be more literal than that?
However, there is also plenty of evidence from the text itself (in Revelation) that the plagues are indeed literal. Consider:
"3And the second angel poured out his vial upon the sea; and it became as the blood of a dead man: and every living soul died in the sea. 4And the third angel poured out his vial upon the rivers and fountains of waters; and they became blood. 5And I heard the angel of the waters say, Thou art righteous, O Lord, which art, and wast, and shalt be, because thou hast judged thus. 6For they have shed the blood of saints and prophets, and thou hast given them blood to drink; for they are worthy." Rev. 16:3-6
We can clearly see here that if these two plagues are not literal then the irony is lost. The purpose is obvious - they have killed the saints/prophets, so now they are getting blood to drink. More evidence of literal plagues:
"8And the fourth angel poured out his vial upon the sun; and power was given unto him to scorch men with fire. 9And men were scorched with great heat, and blasphemed the name of God, which hath power over these plagues: and they repented not to give him glory." Rev. 16:8-9
This plague must also be literal - the description of it shows that.
"10And the fifth angel poured out his vial upon the seat of the beast; and his kingdom was full of darkness; and they gnawed their tongues for pain,11And blasphemed the God of heaven because of their pains and their sores, and repented not of their deeds." Rev. 16:10-11
This shows that their pains and sores are literal, which also refers back to vial 1 in Revelation 16 where a "noisome and grievous sore" falls upon those who have the mark of the beast. That means that vial 1 must be literal as well.
Here's yet another description that shows the plagues are literal:
"4And it was commanded them that they should not hurt the grass of the earth, neither any green thing, neither any tree; but only those men which have not the seal of God in their foreheads. 5And to them it was given that they should not kill them, but that they should be tormented five months: and their torment was as the torment of a scorpion, when he striketh a man. 6And in those days shall men seek death, and shall not find it; and shall desire to die, and death shall flee from them." Rev. 9:4-6
The description that men shall "seek death" and "not find it" shows that these plagues are actually literal - something very, very painful is happening to the human race right here. In addition, this affects virtually all of the human race except those that are sealed (which we know = 144,000).
Yet more evidence:
"15And the four angels were loosed, which were prepared for an hour, and a day, and a month, and a year, for to slay the third part of men. 16And the number of the army of the horsemen were two hundred thousand thousand: and I heard the number of them. 17And thus I saw the horses in the vision, and them that sat on them, having breastplates of fire, and of jacinth, and brimstone: and the heads of the horses were as the heads of lions; and out of their mouths issued fire and smoke and brimstone. 18By these three was the third part of men killed, by the fire, and by the smoke, and by the brimstone, which issued out of their mouths. 19For their power is in their mouth, and in their tails: for their tails were like unto serpents, and had heads, and with them they do hurt. 20And the rest of the men which were not killed by these plagues yet repented not of the works of their hands, that they should not worship devils, and idols of gold, and silver, and brass, and stone, and of wood: which neither can see, nor hear, nor walk:" Rev. 9:15-20
Obviously, if the fire and smoke and brimstone is "symbolic", we have to wonder how something symbolic could kill 1/3 of men. Therefore, it is obvious from just the very description given, that this plague must be literal - literal fire, smoke, and brimstone goes from their mouths. John must here be describing modern weaponry, and it is my belief that his description of "horses" (which you ride into battle) fits the description of tanks, airplanes, and helicopters.
Some have suggested that the sixth seal is symbolic, and not actually literal at all. This interpretation will be shown to be false:
"12And I beheld when he had opened the sixth seal, and, lo, there was a great earthquake; and the sun became black as sackcloth of hair, and the moon became as blood; 13And the stars of heaven fell unto the earth, even as a fig tree casteth her untimely figs, when she is shaken of a mighty wind. 14And the heaven departed as a scroll when it is rolled together; and every mountain and island were moved out of their places." Rev. 6:12-14
Christ's words show that it is literal:
"29Immediately 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:" Mt. 24:29
"24But in those days, after that tribulation, the sun shall be darkened, and the moon shall not give her light, 25And the stars of heaven shall fall, and the powers that are in heaven shall be shaken." Mk. 13:24-25
Isaiah's words prove that it is literal:
"10For 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. 13:10
We can see, then, that the sixth seal is actually literal, and that the descriptions given in it are literal. The sun will appear black, the moon blood red (will not give her light) and it will appear as though the stars are falling (probably because something catastrophic happens to the earth's axis).
In conclusion, proof has been given that the plagues in Revelation are indeed literal. When John says the entire ocean turns blood red, he means it (and the angel shows this). This will actually literally happen to the ocean. Anyone who claims that the events in Revelation are symbolic goes against all the Biblical evidence to the contrary.
"21For then shall be great tribulation, such as was not since the beginning of the world to this time, no, nor ever shall be. 22And except those days should be shortened, there should no flesh be saved: but for the elect's sake those days shall be shortened." Mt. 24:21-22
These verses alone (and there are more) prove that the plagues in the book of Revelation must be mostly literal. This time of tribulation in the book of Revelation must be even greater than the Holocaust, greater than anything Mao or Stalin did, greater than any war that was ever fought. Indeed, so great is the tribulation that unless those days were shortened (and I believe it is a literal shortening of the 24 hour day) everyone would die. But there is even more evidence that the plagues are literal in the book of Daniel:
"1And at that time shall Michael stand up, the great prince which standeth for the children of thy people: and there shall be a time of trouble, such as never was since there was a nation even to that same time: and at that time thy people shall be delivered, every one that shall be found written in the book. " Dan. 12:1
This must be what Christ is referring to in Mt. 24. Yet there is even more evidence:
"25And there shall be signs in the sun, and in the moon, and in the stars; and upon the earth distress of nations, with perplexity; the sea and the waves roaring; 26Men's hearts failing them for fear, and for looking after those things which are coming on the earth: for the powers of heaven shall be shaken." Lu. 21:25-26
This verse plainly proves the events in Revelation are not symbolic at all, but are literal. The nations are distressed and "perplexed." It is interesting to study the word "perplexed" in Greek:
Perplexity, #640, aporia, (Thayer) the state of one who is in perplexity. Vine's: "akin to A, No. 1, is translated "perplexity" in Luk 21:25 (lit., "at a loss for a way," a, negative, poros, "a way, resource"), of the distress of nations, finding no solution to their embarrassments; papyri illustrations are in the sense of being at one's wit's end, at a loss how to proceed, without resources."
Obviously they are "at a loss for a way" because of the terrible things that are happening to the planet. The other words are also useful to study: Distress, #4928, synoche, (Thayer)
1) a holding together, a narrowing
2) the contracting part of a way
3) metaph. straits, distress, anguish
Looking after, #4329, prosdokia, (Thayer) 1) expectation (whether good or evil).
So great and terrible will be the events happening to the earth that people will actually die of heart attacks (men's hearts failing them for fear). What could possibly be more literal than that?
However, there is also plenty of evidence from the text itself (in Revelation) that the plagues are indeed literal. Consider:
"3And the second angel poured out his vial upon the sea; and it became as the blood of a dead man: and every living soul died in the sea. 4And the third angel poured out his vial upon the rivers and fountains of waters; and they became blood. 5And I heard the angel of the waters say, Thou art righteous, O Lord, which art, and wast, and shalt be, because thou hast judged thus. 6For they have shed the blood of saints and prophets, and thou hast given them blood to drink; for they are worthy." Rev. 16:3-6
We can clearly see here that if these two plagues are not literal then the irony is lost. The purpose is obvious - they have killed the saints/prophets, so now they are getting blood to drink. More evidence of literal plagues:
"8And the fourth angel poured out his vial upon the sun; and power was given unto him to scorch men with fire. 9And men were scorched with great heat, and blasphemed the name of God, which hath power over these plagues: and they repented not to give him glory." Rev. 16:8-9
This plague must also be literal - the description of it shows that.
"10And the fifth angel poured out his vial upon the seat of the beast; and his kingdom was full of darkness; and they gnawed their tongues for pain,11And blasphemed the God of heaven because of their pains and their sores, and repented not of their deeds." Rev. 16:10-11
This shows that their pains and sores are literal, which also refers back to vial 1 in Revelation 16 where a "noisome and grievous sore" falls upon those who have the mark of the beast. That means that vial 1 must be literal as well.
Here's yet another description that shows the plagues are literal:
"4And it was commanded them that they should not hurt the grass of the earth, neither any green thing, neither any tree; but only those men which have not the seal of God in their foreheads. 5And to them it was given that they should not kill them, but that they should be tormented five months: and their torment was as the torment of a scorpion, when he striketh a man. 6And in those days shall men seek death, and shall not find it; and shall desire to die, and death shall flee from them." Rev. 9:4-6
The description that men shall "seek death" and "not find it" shows that these plagues are actually literal - something very, very painful is happening to the human race right here. In addition, this affects virtually all of the human race except those that are sealed (which we know = 144,000).
Yet more evidence:
"15And the four angels were loosed, which were prepared for an hour, and a day, and a month, and a year, for to slay the third part of men. 16And the number of the army of the horsemen were two hundred thousand thousand: and I heard the number of them. 17And thus I saw the horses in the vision, and them that sat on them, having breastplates of fire, and of jacinth, and brimstone: and the heads of the horses were as the heads of lions; and out of their mouths issued fire and smoke and brimstone. 18By these three was the third part of men killed, by the fire, and by the smoke, and by the brimstone, which issued out of their mouths. 19For their power is in their mouth, and in their tails: for their tails were like unto serpents, and had heads, and with them they do hurt. 20And the rest of the men which were not killed by these plagues yet repented not of the works of their hands, that they should not worship devils, and idols of gold, and silver, and brass, and stone, and of wood: which neither can see, nor hear, nor walk:" Rev. 9:15-20
Obviously, if the fire and smoke and brimstone is "symbolic", we have to wonder how something symbolic could kill 1/3 of men. Therefore, it is obvious from just the very description given, that this plague must be literal - literal fire, smoke, and brimstone goes from their mouths. John must here be describing modern weaponry, and it is my belief that his description of "horses" (which you ride into battle) fits the description of tanks, airplanes, and helicopters.
Some have suggested that the sixth seal is symbolic, and not actually literal at all. This interpretation will be shown to be false:
"12And I beheld when he had opened the sixth seal, and, lo, there was a great earthquake; and the sun became black as sackcloth of hair, and the moon became as blood; 13And the stars of heaven fell unto the earth, even as a fig tree casteth her untimely figs, when she is shaken of a mighty wind. 14And the heaven departed as a scroll when it is rolled together; and every mountain and island were moved out of their places." Rev. 6:12-14
Christ's words show that it is literal:
"29Immediately 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:" Mt. 24:29
"24But in those days, after that tribulation, the sun shall be darkened, and the moon shall not give her light, 25And the stars of heaven shall fall, and the powers that are in heaven shall be shaken." Mk. 13:24-25
Isaiah's words prove that it is literal:
"10For 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. 13:10
We can see, then, that the sixth seal is actually literal, and that the descriptions given in it are literal. The sun will appear black, the moon blood red (will not give her light) and it will appear as though the stars are falling (probably because something catastrophic happens to the earth's axis).
In conclusion, proof has been given that the plagues in Revelation are indeed literal. When John says the entire ocean turns blood red, he means it (and the angel shows this). This will actually literally happen to the ocean. Anyone who claims that the events in Revelation are symbolic goes against all the Biblical evidence to the contrary.
These people are gnawing on their tongues BECAUSE of the pains and sores...their tongues aren't the pains and sores. 
So you don't consider forcing folks as telling them...take the mark or you're killed? That isn't forcing?
