In the Bible, trumpets are often connected with destruction (Jer 6:1) so the Seven Trumpets describe Destroyer's plans for destroying God's earth. A trumpet call was often used to call the people of God together for battle, but a trumpet was also sounded by a leader stirring up a rebellion against God. Examples are:

The seven messengers with the seven trumpets were not sent by God, so they represent a rebellion against his plans.
I saw the seven messengers who stand in the face of God, and seven trumpets were given to them (Rev 8:2).
They will attempt to destroy the earth, despite God's instructions that it should be preserved.

In Jesus' plan, John saw four messengers who wanted to destroy God's good creation. A powerful angel holding the seal of God, declared that they were not allowed to harm the earth or the sea, until the full number of Jews had come to faith in Jesus.

I saw four messengers standing at the four corners of the earth, holding back the four winds of the earth to prevent any wind from blowing on the land or on the sea or on any tree. Then I saw another angel coming up from the east, having the seal of the living God. He called out in a loud voice to the four messengers who had been given power to harm the land and the sea: 'Do not harm the land or the sea or the trees until we put a seal on the foreheads of the servants of our God' (Rev 7:1-4).
The images in this passage were probably familiar to John's listeners, but they are not part of our modern language. The "corners of the earth" is an expression describing the entire earth. The modern equivalent of the four corners is the word "global".

The four winds are a description of the "weather system". Therefore, the four winds from the corners of the earth represent the "global weather system". John was describing changes in the global weather system. The four messengers wanted to bring about a change in global weather patterns would produce dramatic global climate change that would harm the earth, the trees and the sea. The four messengers have evil intent, but another angel carrying the seal of God prevents them from acting to harm the earth.

Their declaration prevents the spiritual powers of evil from wrecking the created world, before the Kingdom of God comes to fulness, and once that happens, they will not have the authority on earth to do it.

When the seven messengers took up their trumpets, a powerful angel took up the prayers of the saints and offered them on the altar before the throne of God. These were the prayers prayed against the four messengers that wanted to destroy the earth and sea. The angel of God threw are fire from the altar on to the earth. The outcome of this actions was seen on earth.

There came peals of thunder, rumblings, flashes of lightning and an earthquake (Rev 8:5).
These events represent the release of God's presence and power on earth against the seven messengers wanting to do harm.

The cosmos dominator that controlled the initiation of the seven trumpets was Death (see Death Reigned). Blood is mentioned at various places in the text describing the trumpets. This blood does not mean much except that it is a sign that Death is deeply involved in what happened. The seven trumpets describe Death plan for the season when Jesus is bringing in the Kingdom of God. Fortunately for the church and the world, Death's plans fail.

Interpreting the first four trumpets is almost impossible without understanding that disconnection between the actions taken and the outcomes that follow. The key to solving this problem is understanding that the first four trumpets described the things the Death wants to do, but is unable to achieve. They also describe what he will actually do when he fails to achieve his goals.

It seems that Death had plans to send the evil spirits that he controlled to destroy the earth, the trees, the grass, the rivers and the sea, and many of the animal living in them, and to darken the atmosphere in some way, but he was stymied by God and the prayer of the saints.

The angel with the seal had authority to prevent this destruction, and the prayers of the saints had released his authority on earth to stop Death from aching his objectives. When he was prevented from carrying out his plans, Death got angry and went off to destroy some other things that were important to God.

The text announcing the seven trumpets describes both the even planned by Death which was stymied, and the action he will achieve instead.

Seven Trumpets — Death/Destroyers Plan
Evil Planned Evil Achieved
1 Destroy a third of the earth, a third of the trees and all of the grass. A Fizzer compared to the activities of God's angel.
2 Destroy the sea and a third of the life in it and a third of the boats that earn their living on the sea. Undermine the legal system given by God on blazing mountain and undermine confidence in it amongst the people (sea).
3 Destroy a third of the springs and rivers by making them bitter. Destroying the church in an important nation (star) by causing the people to divide into bitterness.
4 Make a third of the sun, the moon and the stars go dark, so the world become dark. Attacks a national leader of Israel (sun, moon and the stars) and exposing the darkness of the nation.
5 Death releases Destroyer and his following spirits from the Abys to increase his power. Destroyer defeats Death and takes his place, but is prevented from touching the created world. He has to focus on torment humans without spiritual protection.
6 Seeks to start a massive war in the Middle East (near the Euphrates) by gathering kings to battle. I believe that this effort failed due to the prayers of the saints. The 200 million cavalry indicates the number of spirits under the Destroyer's authority.
7 The kingdom of the world has become the kingdom of our Lord and of his Messiah, and he will reign for ever and ever (Dan 11:15).

The contrast between the angel of God and the sounding of the first trumpet is huge. The former brought the presence and activity of God to earth (represented by lightning, thunder and earthquakes). The latter could only achieve hail and fire, which symbolise destruction and blood, which symbolise death.

Death failed in his efforts to destroy all the grass and a third of the trees, but the grass and trees were still in existence and growing strong in Rev 9:4 when the fifth trumpet was sounded by a messenger of Death. The sounding of the first trumpet will be a fizzer. Death's plans to harm the earth will fail.

The great mountain burning with fire released by the second trumpet is a reference to Mount Sinai, where God gave his system of law to Moses.

Mount Sinai was covered with smoke, because the Lord descended on it in fire. The smoke billowed up from it like smoke from a furnace, and the whole mountain trembled violently (Exodus 19:18).
When God came down to give the law the mountain smoked with fire. In Revelation, the sea represents the peoples, multitudes, nations and languages (Rev 17:15). A blazing mountain falling into the sea represents the people of the world throwing of God's law. He gave the laws of Moses so people would know how to government themselves in a just way. The rejection of God's system of law and justice will just create shock waves that will spread out to harm the people and nations of the world. Death will deceive the people of the world in to rejecting God's way of government, opening the way for the Beast to rise to power.

The third trumpet caused a great star burning like a torch to fall from heaven. In Revelation, seven stars were the angels of the seven churches (Rev 1:20). This falling star represents the decline of the church in an important part of the world. This church falls away when it comes under the control of the spiritual powers of evil.

The fall of this church turns the waters bitter. Water is the life of the spirit, so this This is a description of spiritual life in that part of the world turning bitter. The church that falls will become bitter and be a source of spiritual death. The fall of this star will produce great bitterness for the people who live under its influence.

The falling shines like a torch. This is not God's light, but it makes the fall of the star highly visible. The modern church with the greatest visibility is the United States. Its divisions and bitterness are being played out visibly in the news media for all the world to see. The failure of Christianity in the United States will do great harm in the world and allow terrible evil forces to rise to power.

The fourth trumpet struck the sun, the moon and the stars. In Revelation, the sun, the moon and the stars represent the nation of Israel (Rev 12:1-3). Their darkening could represent the collapse of the government of the state of Israel or the downfall of powerful ruler of the nation. This it will be a time of darkness and fear for those living within this this nation.

The current government of Israel is divided with no party being able to gain a settled majority in the Knesset. Long-time President Benjamin Netanyahu has been deposed from office and faces corruption charges.

By controlling the United States political system, Israel gains such immense power that allows it to impose its will on much of the world. However, that influence is weakening, because various international organisations have recently exposed the true nature of the apartheid system that has been established in the nation. If this crisis exposes the true character of the State of Israel, the people who have supported Israel as a force for good, will begin to understand that it has been manipulated and controlled by the forces of evil.

When the fifth Trumpet is sounded evil spiritual powers that have been locked up in the abyss since the time of Noah are set free to do evil on earth. They are led by cosmos dominator called Destroyer (Rev 9:11). He had organised a season of terrible destruction on earth when he was the cosmos dominator that controlled the earth during the Millennium of Darkness between the fall and the flood. He and his followers were locked in the abyss for their troubles, significantly reducing the amount of evil on earth. John saw a star that had already fallen from the sky.

The fifth angel sounded his trumpet, and I saw a star that had fallen from the sky to the earth (Rev 9:1). This is the consequence of the previous trumpet, so John is referring to an angel of the church that has already fallen. The star was given the key to the shaft of the Abyss. When he opened the Abyss, smoke rose from it like the smoke from a gigantic furnace. The sun and sky were darkened by the smoke from the Abyss (Rev 9:2-3).

The angel that fell is given the key to the Abyss, which is the dwelling place of the demonic powers that had been confined there after Noah's flood. A huge number of evil spiritual powers are released on the earth. They are led by an angel whose name is Destruction (Rev 9:1-11).

It seems that the words and actions of the failing church allowed the door of the abyss so the trapped spirits could escape. I presume this church this church had stopped caring for God's creation responsibly and had not challenged people and businesses who had seriously harmed the creation. Maybe it had participated in the destruction of the earth through wreckless mining, burning forests and wars that wreaked terrible destruction on the earth. God is just.

I suspect that Destroyer and his followers appealed to God's justice by claiming that it is not fair for them to be locked for trying to destroy the earth at the time of Noah, when the followers of Jesus are doing the same thing. If the angels confined in the abyss for attempting to wreck the earth said to God that they had not done anything worse than the failed church, he would have to release them to be fair. Anyway, he is released onto the earth again.

This concession would allow the angel to open the abyss and let the entrapped spirits out. However, their release was subject to a serious constraint. They were not allowed to do harm to the grass, the trees or the earth. They had seriously harmed the earth during the time of Noah, so they will be released on the condition that they never try to do that again.

They were told not to harm the grass of the earth or any plant or tree, but only those people who did not have the seal of God on their foreheads (Rev 9:4).

They would direct all their energies to attacking humans who did not have the seal of God. This event is a terrible woe for the inhabitants of the earth (Rev 9:12). Evil spirits that have been locked up in the Abyss since the time of Noah will be released back onto the earth again. Their release will bring about a vast increase in evil on earth.

The cosmos dominator that controls this great army of spirits called Destroyer (Rev 9:11). He will rise up to seize control of Death and his army of spirits and begin to torment people. Death will be constrained and lose control over the situation. He will not be able to kill people who are being tormented (Rev 9:5-6). The seventh trumpet shifts power from Death to Destroyer and allows darkness spread across the earth (Rev 9:2).

When the sixth trumpet is sounded, Destroyer attempts to gather some nations for battle in the Middle East, near the Euphrates River. This river flows through Syria and Iraq, so it could be a description of the wars that have occurred their recently, because several nations were engaged in the struggle. He wanted to kill a third of humans on earth, but he might not be able to achieve his goal.

The reference to 200 million cavalry soldiers is not the size of the human army, as if is often assumed, but is the number of evil spirits that are controlled by Destroyer when he starts this action (One group is probably controlled by Gog (Ezek 38,39). Of course, God has millions of angels at his disposal to fight against him and constrain his endeavours.

When the seventh trumpet sounded, Death, Destroyer, and their followers are totally defeated and the Kingdom of God comes to fulness on earth.

The kingdom of the world has become the kingdom of our Lord and of his Messiah, and he will reign for ever and ever (Rev 11:15).
The speaks for itself. Brilliant.