Since the fourth trumpet, the last three trumpets were foreboding, because each caused the eagle to express a "woe" (Rev 8:13). Their expression of sorrow was for those remaining on earth, because these coming judgments were God’s expression of wrath directly on human beings. And as each trumpet sounds, a countdown of woes ensues.

After the fourth trumpet:

Then I looked, and I heard an eagle flying in midheaven, saying with a loud voice, "Woe, woe, woe to those who dwell on the earth, because of the remaining blasts of the trumpet of the three angels who are about to sound!" (Rev 8:13)

After the fifth trumpet:

The first woe is past; behold, two woes are still coming after these things. (Rev 9:12)

The first woe was a response to the implication of opening the bottomless pit and the subsequent stinging torment of all human beings without the seal of God on their foreheads (Rev 9:1-12).

After the sixth trumpet:

The second woe is past; behold, the third woe is coming quickly. (Rev 11:14)

The second woe was a response to the implication of releasing the four angels bound at the Euphrates River and the subsequent killing of one third of mankind (Rev 9:13-21).

After the seventh trumpet:

Because the eagle's woe is for "those who dwell on the earth," the third and last woe pertains to the only remaining judgments against those left on earth, which is the "reaping" by the angel (Rev 14:18-20).

The reaping figuratively speaks of gathering the "ripe" grapes and throwing them into the great wine press of God's wrath "outside the city" (Rev 14:18-19), which is a reference to the bowl judgments that follow (Rev 16:1-21). This period of reaping includes the angelic assistance of carrying out Jesus Christ's judgment at Armageddon, because it is Jesus who treads upon the grapes in the great wine press of God's wrath (Rev 19:15-21).

When John sees the sign of the seven angels with the seven plagues, he sees them before they emerge from within the Temple of God (Rev 15:1, 6). The sign is "great and marvelous," because these angels "are the last and in them the wrath of God is finished."

The people "who have overcome the beast and his image and the number of his name" and have "harps of God" are saints of the Great Tribulation. Since the "sea of glass" is associated with the throne of God (Rev 4:6), the saints of the Great Tribulation have the honor of singing before God in His throne, the four living creatures, and the elders.

The appearance of these seven angels with their seven plagues, inside the Temple of God, and what they represented caused the saints of the Great Tribulation to sing three praises to God.

The first song was the Song of Moses (Rev 15:3; Ex 15:1-18). The Song of Moses memorialized the deliverance of Israel from Egypt and the spectacular nature of the Exodus. Celebrating God's victory over Egypt was public acknowledgment of God's sovereign rule over the universe.

Just as when Satan appears to be in control at this time, as Pharaoh was in his time, the saints of the Great Tribulation know otherwise as they sing in acknowledgment of God's sovereign rule and judgment of evil.

The second song of praise was the Song of the Lamb that only the 144,000 sealed bond servants of God could originally sing; but, now the saints of the Great Tribulation know the song as well. However, John does not reveal what the Song of the Lamb is.

Then I looked, and behold, the Lamb was standing on Mount Zion, and with Him 144,000, having His name and the name of His Father written on their foreheads. And I heard a voice from heaven, like the sound of many waters and like the sound of loud thunder, and the voice which I heard was like the sound of harpists playing on their harps. And they sang a new song before the throne and before the four living creatures and the elders. And no one could learn that song except the 144,000 who had been purchased from the earth. These are the ones who are not defiled with women, for they are virgins. These are the ones who follow the Lamb wherever He goes. These have been purchased from among men as first fruits to God and to the Lamb. And no lie was found in their mouth; they are blameless. (Rev 14:1-5, LSB)

The third song of praise is short and asserts God's holy, righteous, and powerful nature deserving of fear and worship (Rev 15:2b). It places an emphasis on "the kingdom of the world has become the kingdom of our Lord and of His Christ; and He will reign forever and ever" (Rev 11:15-18).

When the seven angels who had the seven plagues come out from the Temple of God, they receive from one of the four living creatures a bowl of God's wrath (Rev 15:6-7), and it appears that each plague is mixed with each corresponding bowl (Rev 21:9).

When examining the first six bowl judgments, a chart is helpful to categorize observations of the text:

The bowls of God's wrath and plagues are significant for the judgments they render:

Bowl 1. Because most surviving human beings are non-Believers (Rev 9:20-21; 13:7-8, 16-18), they are tormented with disfiguring and painful sores.

And the rest of mankind, who were not killed by these plagues, did not repent of the works of their hands, so as not to worship demons, and the idols of gold and of silver and of brass and of stone and of wood, which can neither see nor hear nor walk. And they did not repent of their murders nor of their sorceries nor of their sexual immorality nor of their thefts. (After the Sixth Trumpet, Rev 9:20-21)

And it was also given to him to make war with the saints and to overcome them, and authority over every tribe and people and tongue and nation was given to him. And all who dwell on the earth will worship him, everyone whose name has not been written from the foundation of the world in the book of life of the Lamb who has been slain. If anyone has an ear, let him hear. (After the emergence of the Antichrist, Rev 13:7-8)

And he causes all, the small and the great, and the rich and the poor, and the free men and the slaves, that they be given a mark on their right hand or on their forehead, and that no one will be able to buy or to sell, except the one who has the mark, either the name of the beast or the number of his name. Here is wisdom. Let him who has understanding calculate the number of the beast, for it is the number of man; and his number is 666. (After the False Prophet exercises his authority, Rev 13:16-18)

Bowl 2. With the poisoning of all salt water and the killing of all living creatures within it, billions of people are without their primary food source. This also devastates the economy of many nations. The Second Trumpet earlier poisoned 1/3 of the sea and its sea life (Rev 8:8-9).

8) And the second angel sounded, and something like a great mountain burning with fire was thrown into the sea; and a third of the sea became blood, and a third of the creatures which were in the sea—those which had life—died; and a third of the ships were destroyed. (Second Trumpet, Rev 8:8-9)

Bowl 3. With the poisoning of all fresh water, governments will be severely tested and societies could quickly collapse. Among numerous issues: drinking water is confined to limited supplies of packaged goods, filtration systems will be required, personal hygiene is curtailed, and cooking is restricted. The Third Trumpet earlier poisoned 1/3 of all rivers and water springs, which usually feed into lakes (Rev 8:10-11).

And the third angel sounded, and a great star fell from heaven, burning like a torch, and it fell on a third of the rivers and on the springs of waters. And the name of the star is called Wormwood; and a third of the waters became wormwood, and many men died from the waters, because they were made bitter. (Third Trumpet, Rev 8:10-11)

Bowl 4. Increasing the heat of the sun to "scorching" critically exacerbates the problem of scarce safe water for any use and increases the risk of massive wildfires. And without water, hydroelectric production of electricity ceases. The First Trumpet already burned up 1/3 of the earth (Rev 8:7). The supernatural events of Bowls 1-4 did not cause people to recognize the authority of God or honor Him; instead, they blasphemed His name and did not repent.

And the first sounded, and there came hail and fire, mixed with blood, and they were thrown to the earth; and a third of the earth was burned up, and a third of the trees were burned up, and all the green grass was burned up. (First Trumpet, Rev 8:7, LSB)

Bowl 5. Darkening the Antichrist’s kingdom causes less solar power generation, crop failures, and health problems as evidenced by "pains and sores." The Fourth Trumpet already darkened 1/3 of sun and moon light (Rev 8:12), and people had already experienced the torment of unrequited pain as the result of the Fifth Trumpet (Rev 9:4-10). Now there is more, and the people respond by continuing their dishonor and disobedience of God.

And the fourth angel sounded, and a third of the sun and a third of the moon and a third of the stars were struck, so that a third of them would be darkened and the day would not shine for a third of it, and the night in the same way. (Fourth Trumpet, Rev 8:12)

And they were told not to hurt the grass of the earth, nor any green thing, nor any tree, but only the men who do not have the seal of God on their foreheads. And they were not permitted to kill anyone, but to torment for five months, and their torment was like the torment of a scorpion when it stings a man. And in those days men will seek death and will never find it; they will long to die, and death flees from them. And the appearance of the locusts was like horses prepared for battle. And on their heads appeared to be crowns like gold, and their faces were like the faces of men. And they had hair like the hair of women, and their teeth were like the teeth of lions. And they had breastplates like breastplates of iron, and the sound of their wings was like the sound of chariots, of many horses running to battle. And they have tails like scorpions, and stings; and in their tails is their power to hurt men for five months. (Fifth Trumpet, Rev 9:4-10)

Bowl 6. The drying of the Euphrates River sets in motion the conflict at Armageddon by enabling the kings from the east to mobilize their troops over land. With the drying of the Euphrates River, a demonic spirit comes out of Satan, the Antichrist and the False Prophet (Rev 16:13). A literal reading of the text suggests that the demonic spirits were indwelling; but, a figure of speech is possible indicating that these demonic spirits were called forth. Regardless, these demonic spirits influenced human kings such that they would gather their armies at Armageddon (Rev 16:14-16). It is reminiscent of Pharaoh of the Exodus, who is so mad at God and the people of Israel, that he sought to destroy them.

Thus I will harden Pharaoh’s heart with strength, and he will pursue them; and I will be glorified through Pharaoh and all his army, so that the Egyptians will know that I am Yahweh." And they did so. Then the king of Egypt was told that the people had fled, and the heart of Pharaoh and his servants was changed toward the people, and they said, "What is this we have done, that we have let Israel go from serving us?" So he made his chariot ready and took his people with him; and he took six hundred choice chariots and all the other chariots of Egypt with officers over all of them. (Ex 14:4-7)

Instead of repenting, amidst this great suffering, the people did not fear God, blasphemed His name and failed to recognize that He was Lord of all. People preferred to follow the "great men of earth" and would be unable to hear the gospel (Rev 18:23).