Revelation 9:8-14
(Rev 9:8 KJV)
And they had hair as the hair of women, and their teeth were as the teeth of lions.

When locust are in flight, the small hairs on their legs and bodies would indicate the speediness in which they would be carrying out their mission. Keep in mind that they have a time limit on their mission and that is symbolically set at five months. The hair of women flowing in the wind would give a picture of the swiftness of these locusts. Then we are told that these locusts have teeth of lions.
(1 Pet 5:8 KJV) Be sober, be vigilant; because your adversary the devil, as a roaring lion, walketh about, seeking whom he may devour: The teeth of lions shows us that these demonic forces will be fierce and devouring. Satan as a lion has no love for Christians and he has no love for those who follow him either. He hates all people with a vengeance. This is why these devils are being shown as fierce with the teeth of lions. If anyone has ever seen a lion devour prey, they literally rip them apart piece by piece. This is what Satan does to those who follow him. Piece by piece he pulls apart their lives.

(Rev 9:9 KJV)
And they had breastplates, as it were breastplates of iron; and the sound of their wings was as the sound of chariots of many horses running to battle.

This verse is similar to the vision of Joel concerning the fierceness of the locusts.

(Joel 2:4-8 KJV) The appearance of them is as the appearance of horses; and as horsemen, so shall they run. {5} Like the noise of chariots on the tops of mountains shall they leap, like the noise of a flame of fire that devoureth the stubble, as a strong people set in battle array. {6} Before their face the people shall be much pained: all faces shall gather blackness. {7} They shall run like mighty men; they shall climb the wall like men of war; and they shall march every one on his ways, and they shall not break their ranks: {8} Neither shall one thrust another; they shall walk every one in his path: and when they fall upon the sword, they shall not be wounded.

In the Revelation verse we are told that these demon locusts have breastplates of iron. The breastplate was an integral part of the soldier’s defense. While wearing the breastplate an arrow or spear could not penetrate the vital organs. These locust wearing the breastplates are signifying the fact that they cannot be stopped from their divinely appointed mission. Whatever their mission is and to those whom it is aimed at will receive whatever God has determined for them to receive. This second vision of John seems to indicate that these judgments are primarily coming against those who are idolaters. In Joel, the primary judgment was coming against Judah who became steeped in idolatry. God is using the vision of Joel as a parallel judgment to the one coming on the earth.

(Jer 51:27 KJV) Set ye up a standard in the land, blow the trumpet among the nations, prepare the nations against her, call together against her the kingdoms of Ararat, Minni, and Ashchenaz; appoint a captain against her; cause the horses to come up as the rough caterpillars.

In Jeremiah and Joel, we read, as we do in Revelation 9:9, that these demon locusts will come with the swiftness of an invading army. The “rough caterpillars” in Jeremiah 51:27, are the locusts. John heard these demon locusts as if they were the sound of an invading army. This means that they will be coming against those who continue in their unbelief and they will be coming with the unrelenting fierceness of an invading army.

(Rev 9:10 KJV)
And they had tails like unto scorpions, and there were stings in their tails: and their power was to hurt men five months.

Once again John is pointing out that these devils will not be allowed to kill the people they are sent to bring judgment on. Just as Satan was not allowed to kill Job but only to afflict him. These devils are afflicting those who are still in unbelief. These judgments will not be upon the true Christians but upon unbelievers. As a scorpion stings its victims, these demon locusts will be stinging their victims but without death. It may be that they will bring unbelievers further into unbelief and cause them stray farther from the Lord. If this is the case, then God would be readying the world for Judgment day as the increase in false gospels and false teachers will increase. Once again John mentions the time limit of five months and this time should not be taken literally since we are dealing with apocalyptic and visionary language. The five months tell us that this judgment has a projected time limit to it.

(Rev 9:11 KJV)
And they had a king over them, which is the angel of the bottomless pit, whose name in the Hebrew tongue is Abaddon, but in the Greek tongue hath his name Apollyon.

In this verse we are introduced to the king over the bottomless pit. The two names which describe him are “Abaddon” and “Apollyon.” The name “abaddon” in the Hebrew carries with it the meaning of “ruin or destruction.” The name “Apollyon” carries with it the meaning of “to destroy.” The name “Apollyon” may come from the Roman god “Apollo” who was the patron god of the Roman Empire but the name Apollo goes back as far as the fifth century BC with the Greeks. In fact, history records that locusts were considered the creature of Apollo plus he was also known as the god of pestilence. John is not advocating a belief in the false god Apollo but he is making an association of ruin and destruction with the two names. It is not clear whether this angel who was king over the bottomless was Satan or another angel. We know that Satan’s mode of operation is nothing but chaos and destruction and he is head of the fallen angels at this point until he will be cast into the lake of fire at the end of time. We also know that there will come a time when all his angels will be released along with him to make war against the Christians and overcome them right before the return of the Lord Jesus Christ. We will see this detailed in Revelation 20.

(Rev 9:12 KJV)
One woe is past; and, behold, there come two woes more hereafter.

The first woe which was introduced by the angel in 8:13 is now complete but the second woe which is the sixth trumpet and the third woe which is the seventh trumpet are soon to be sounded. Now the vision is moved to the end of the five months as the other trumpets are ready to sound.

(Rev 9:13 KJV)
And the sixth angel sounded, and I heard a voice from the four horns of the golden altar which is before God,

The seventh seal and the seven trumpets are tied to the prayers of the Saints as we are once again brought back into the throne room where the focus is the golden altar where the prayers of the Saints were mixed with incense and then cast to the earth. The four horns of the altar are emphasized here. Four is the number of universality, so we can conclude by this that the prayers of the Saints are coming in from all over the world plus the judgment of God is going out through all the earth with limitations at this particular point in the second vision. The voice which is heard may be the voice of another angel or it could be the voice of the Lord Jesus Christ.

(Rev 9:14 KJV)
Saying to the sixth angel which had the trumpet, Loose the four angels which are bound in the great river Euphrates.

These four angels differ from the four angels on the four corners of the earth in Revelation 7:1. Here a specific river is mentioned plus the angels in Revelation 7:1 are holding back the forces of evil while these four angels have been loosed. The Euphrates river was the limit of the land which was promised to Abraham back in Genesis. It is also one of the rivers which is mentioned flowing out of the Garden of Eden.
(Gen 15:18 KJV) In the same day the LORD made a covenant with Abram, saying, Unto thy seed have I given this land, from the river of Egypt unto the great river, the river Euphrates:  Now John is not seeing a physical river in his vision but he is seeing the beginning of the onslaught of demonic forces which will soon envelop the earth against the unbelievers. The river Euphrates was east of Israel. (Rev 7:2 KJV) And I saw another angel ascending from the east, having the seal of the living God: and he cried with a loud voice to the four angels, to whom it was given to hurt the earth and the sea, The angel who told the four angels of Rev. 7:1 to not hurt those who have the seal of God on them. Remember the term “east” is defined by its usage. (Rev 16:12 KJV) And the sixth angel poured out his vial upon the great river Euphrates; and the water thereof was dried up, that the way of the kings of the east might be prepared. In the sixth vial judgment, the Euphrates was dried up so the kings of the east could march. It could be that we are seeing the same action being performed on the Euphrates in both Revelation 9:14 and 16:12. Keep in mind that we are seeing parallel visions of the same events only they become more intense as we continue on.