Then the fifth angel sounded a trumpet and I beheld a star falling out the sky to the earth, and it was given to him the key of the pit of the abyss.
Then he opened the pit of the abyss, and smoke ascended out of the pit like the smoke of an enormous furnace, and the sun was obscured, and the air, from the smoke of the pit.
Then out of the smoke came locusts to the earth, and it was given to them liberty to act as the scorpions of the earth have liberty to act.
And it was told to them that they are not to spoil, injure, or damage
- the grass of the earth,
- nor every green thing,
- nor every tree,
but only the people who do not have the seal of the Lord upon the forehead.
And it was given to them not to put them to death, but rather in order that they will be tormented and put to the test five months, and the inquisition of them is as the torment of a scorpion, when it stings a person.
And in those days the people will seek death and will not ever find it, and will long to die and death flees from them.
Revelation 9:1-6

Recap of Spiritual Symbology
Spiritual interpreters apply general categories to John’s vision.
- Falling star—Satan cast out of heaven.
- Key—Permission and capability to release demonic forces.
- Abyss—That ancient antediluvian prison where God remanded insurgent, now fallen, angels.
- Smoke—Spiritual forces of evil, lying wonders, deception.
- Locusts—Demonic inquisitors with limited power to torture but not kill or destroy.
Those bearing God’s seal of protection on their foreheads—as John had witnessed happening in between the breaking of the sixth and the seventh seals—are to be spared. Ezekiel had witnessed a similar sealing of the faithful remnant before God judged Jerusalem.
Now the glory of the God of Israel had gone up from the cherub on which it rested to the entryway of the temple. The Lord called to the man clothed in linen who had the writing case at his side and said to him, “Go through the city, through Jerusalem, and put a mark on the foreheads of those who sigh and groan over all the abominations that are committed in it.”
To the others he said in my hearing, “Pass through the city after him and kill; your eye shall not spare, and you shall show no pity.
Ezekiel 9:3-5 (NRSV, modifications mine)
God had also spared the Israelites the worse of the plagues in Egypt, most notably the plague of darkness. God’s people remained in light the entirety of the three days when the rest of Egypt could not even see their hands before their faces. In other words, God’s people saw all, but those in darkness could not even see the reality right under their noses.

Spiritual Purpose of the Locusts
The last piece is the time frame given to the locusts: five months. Perhaps because a locust’s natural lifespan is five months long, the vision was conveying a limited and not unexpected interval. The relentlessness of their torture would at least not be endless, but last only as long as a locust lives.
That those tortured are not permitted death is irony, mercy, and further torment.
Irony
Irony because for most people the life wish is stronger than any death wish. So often it is life that eludes us, as we live in our ruts, with our distractions that happily keep us from self-reflection and thoughts of deeper things. But when life becomes vividly painful, with nothing strong enough to distract from the constant agony, or numb the relentless suffering, the ultimate release of death is now denied.
Mercy
Mercy because as excruciating as this testing will be, it is for good in the end, that hearts may be laid bear, that souls may be convicted, that spirits may come to know the truths that have been denied, rejected, or suppressed. This is for purposes of life, not death.
Further Torment
Further Torment because the affliction will be severe, the investigation so deeply probative (think of the piercing sting of the scorpion) no place will be left unpunctured, no sting unfelt.
Will this bring fresh meaning to the phrase “battling one’s demons”? Perhaps for John’s audience, such a prospect generated a redoubled commitment to deal with temptation and sin right away. Better to respond to the first prick of conscience before it becomes complicated.
IF we said that we have fellowship with [Jesus] and walk around in the darkness, we are lying [to] ourselves and we do [not live the truth],
And IF we walk around in the light, as He is in the light, we have fellowship with each other, and the blood of Jesus His Son cleanses us from all sin.
IF we say we have not sin, we deceive ourselves and the truth is not in us.
IF we [are acknowledging of] our sins, trustworthy and righteous [is the One] Who forgives us and cleanses us from all unrighteousness.
IF we say we do not trespass, we make Him a liar and His word is not in us.
1 John 1:6-9

Futurist
Interestingly, some with this perspective interpret this oracle as allegorical. The falling star would be the same seen during the third trumpet, named “The Wormwood.” “He” would be the leader of a world-wide religion, and his “key” would be the teaching, rituals, and doctrines he promulgates. This is the black cloud obscuring the sunlight and pure air of the Gospel, and also the locusts representing a spiritual plague of cults and sects, diverse in themselves but all coming under the same large umbrella of false religion.
More literally-minded commentators still understand the falling star as a personage, but prefer the interpretation of Satan, enemy of God. For millennia the word “star” has conceptualized both a shining celestial orb and a highly visible individual such as the star of a show.
Think of Balaam’s famous prophecy,
I see him but not now; I behold him but not near— a star shall come out of Jacob, and a scepter shall rise out of Israel.
Numbers 24:17 (NRSV)
… or Isaiah’s vision, focused on Babylon but also Satan.
How you are fallen from heaven, O Morning Star, son of Dawn! How you are cut down to the ground, you who laid the nations low!
Isaiah 14:12 (NRSV)
Agreeing with those who take a broader, more spiritual view, these scholars also understand the abyss as an angelic prison, and the locusts as a demonic force come to torment unrepentant sinners just before the end of human history. In this case, though, the “piercing” like scorpions represents actual demon possession, spreading their poison throughout a person’s soul yet fiendishly keeping them alive.
This would explain the elusiveness of death, for such a possessed person would no longer be able to exercise their own will, and will be prevented from taking their own lives. Or, even more eerily, perhaps attempts will be made, but none of the methods will have effect—people’s bodies will be impervious to all manner of ordinarily lethal means.
Other interpreters see a vast and unstoppable army in the locusts, fearsome and formidable, perhaps even the army Ezekiel saw in his own vision.
Therefore, mortal, prophesy and say to Gog: Thus says the Lord God: On that day when my people Israel are living securely, you will rouse yourself and come from your place out of the remotest parts of the north, you and many peoples with you, all of them riding on horses, a great horde, a mighty army; you will come up against my people Israel like a cloud covering the earth.
Ezekiel 38:14-16 (NRSV)
Some see Russia as Gog, leading a vast force of assembled military power from nations the world over. Alternatively, at least one commentator sees the locusts as helicopters spraying nerve gas.

The four perspectives taken from Revelation: Four Views A Parallel Commentary, edited by Steve Gregg