The apostle John receives from Jesus (through an angel) a vision of things which must shortly take place:
WEB (Revelation 1:1) 1 This is the Revelation of Jesus Christ, which God gave him to show to his servants the things which must happen soon, which he sent and made known by his angel to his servant, John,
Inspection by Jesus of the 7 assemblies: Éfeze, Smyrna, Pérgamum, Thyatíra, Sardes, Filadélfia en Laodicéa.
After the inspection of the 7 assemblies, John is asked to ascend to heaven so that further heavenly vision can be shown to him:
WEB (Revelation 4:1-2) 1 After these things I looked and saw a door opened in heaven, and the first voice that I heard, like a trumpet speaking with me, was one saying, “Come up here, and I will show you the things which must happen after this.” 2 Immediately I was in the Spirit. Behold, there was a throne set in heaven, and one sitting on the throne
John sees God on his throne and around the throne 24 older persons:
WEB (Revelation 4:4) 4 Around the throne were twenty-four thrones. On the thrones were twenty-four elders sitting, dressed in white garments, with crowns of gold on their heads.
The prophets are already sitting like 24 kings around the throne. They are also anointed and are also among the first fruits and will receive a heavenly resurrection before the 144,000 saints.
He who sits on the throne, the heavenly Father, has a sealed scroll in his right hand, which can only be opened by the Lamb:
WEB (Revelation 5:1,9) 1 I saw, in the right hand of him who sat on the throne, a book written inside and outside, sealed shut with seven seals. 9 They sang a new song, saying, You are worthy to take the book, And to open its seals: For you were killed, And bought us for God with your blood, Out of every tribe, language, people, and nation,
John will get to see what is written in the scroll with the seven seals, a fulfillment of a prophecy of “kings and priests”:
WEB (Daniel 7:27) 27 The kingdom and the dominion, and the greatness of the kingdoms under the whole the sky, shall be given to the people of the saints of the Most High: his kingdom is an everlasting kingdom, and all dominions shall serve and obey him.
The scroll is thus a vision within a vision and describes the purification and sealing of the 144,000, with as spectators; God, the Lamb, the 24 prophets, the four living creatures, the angels and the great multitude.
The Lamb opens the scroll with the seven seals;
When the Lamb opens the first seal of the scroll, the person on the white horse is given a crown, and he goes forth to complete his victory.
This person on the white horse is logically an image of Jesus, who had to wait a long time as King, before the crown is given to him as a sign of received Kingdom power:
WEB (Hebrews 10:12-13) 12 but he, when he had offered one sacrifice for sins for ever, sat down on the right hand of God; 13 from that time waiting until his enemies are made the footstool of his feet.
With the opening of the second seal, the peace of the earth will be removed, resulting in wars. (Rev.6:3,4)
The opening of the third seal means famines. (Rev.6:5,6)
The fourth seal means the death of the 4th part of the earthlings, by wars, food shortages, diseases and by wild beasts. (Rev.6:7,8)
During the fifth seal, there is a persecution of Christians and the number of the 144,000 saints must still be filled. (Rev.6:9-11)
When the sixth seal is opened, we arrive at the end of the great tribulation, the great day of wrath or anger. It starts with a great earthquake, the sun will be darkened, the moon will be as blood and the stars fall from the sky, and every mountain and [every] island is removed from its place (Rev.6:12-17). And the people will be desperately of fear:
WEB (Luke 21:25-26) 25 There will be signs in the sun, moon, and stars; and on the earth anxiety of nations, in perplexity for the roaring of the sea and the waves; 26 men fainting for fear, and for expectation of the things which are coming on the world: for the powers of the heavens will be shaken.
In Revelation 7 is described that the number of 144,000 saints is completed from the twelve tribes of Israel, and that there also can be found a great multitude around the throne.
After the Lamb opened the seventh seal, there was silence in heaven:
WEB (Revelation 8:1) 1 When he opened the seventh seal, there was silence in heaven for about half an hour.
Now, all seals of the scroll with the seven seals are opened by the Lamb.
After this silence an angel throws some altar fire to the earth, and from the throne come lightnings, thunderings, and an earthquake. (Rev.8:5)
Read more at: end time 4. Revelation; the 7 trumpets