It is written:
and from Jesus Christ, the faithful witness, the firstborn from the dead, and the ruler over the kings of the earth. To Him who loved us and washed us from our sins in His own blood, 6 and has made us kings and priests to His God and Father, to Him be glory and dominion forever and ever. Amen. 7 Behold, He is coming with clouds, and every eye will see Him, even they who pierced Him. And all the tribes of the earth will mourn because of Him. Even so, Amen. (Revelation 1:5-7)
The first key to understanding the Book of Revelation lies in comprehending the structure of the Book.
The Book of Revelation is composed of seven visions that the Apostle John was given of the Second Coming of Jesus Christ. Each of these visions begins with the First Coming of Jesus and culminates in the Second Coming (Revelation 1:1-3:22; 4:1-7:17; 8:1-11:19; 12:1-14:20; 15:1-16:21; 17:1-19:21; 20:1-22:21). After the Second Coming, the next vision resets and the same cycle is repeated from a different vantage point.
Each vision begins with Christ coming as Savior (to bring in salvation for whosoever will-Revelation 22:17), and ends with Christ coming in judgement as the mighty Warrior of God. The following chart breaks down the three primary themes of each vision.
First Coming/Triumph Of Christ Over Satan And Bringing Salvation
Revelation 1:5, 7; 4:1-7; 8:1-11; 12:1-5; 15:1-3; 17:14; 20:1-6
Christian Age Increase Of Demonic Power
Revelation 1:5, 7; 2:10; 9:1-12; 13:13; 16:14; 20:7-8
Second Coming Of Christ And Final Defeat Of Satan
Revelation 1:5, 7; 3:21; 14:14, 16; 16:20; 19:11; 22:12-17
First Coming/Triumph Of Christ Over Satan And Bringing Salvation: Revelation 1:5, 7; 4:1-7; 8:1-11; 12:1-5; 15:1-3; 17:14; 20:1-6
Christian Age And Increase Of Demonic Power And Activity: Revelation 1:5, 7; 2:10; 9:1-12; 13:13; 16:14; 20:7-8
Second Coming Of Christ And Final Defeat Of Satan: Revelation 1:5, 7; 3:21; 14:14, 16; 16:20; 19:11; 22:12-17
Please observe that in each of the visions of Revelation, we see the power of Satan increasing throughout the church age (after his defeat by Christ at the First Coming).
One author has well explained the parallelism in Revelation:
“Thus interpreted, each individual church is, as it were, a type, not indicating one definite period in history, but describing conditions which are constantly repeated in the actual life of the various congregations.  Therefore this section appears to span the entire dispensation, from Christ’s first coming to save His people (1: 5) to His second coming to judge all nations (1: 7)….It should be carefully noted that this section also covers the entire dispensation, from the first to the second coming of Christ. The very first reference to Christ pictures Him as having been slain and as now ruling from heaven (5: 5, 6). Towards the end of this section the final judgment is introduced. Notice the impression of the second coming on unbelievers. ‘And they say to the mountains and to the rocks, Fall on us and hide us from the face of the One sitting on the throne, and from the wrath of the Lamb! For it came, the day, the great one, of their wrath; and who is able to stand?’ (6: 16, 17). Now notice the bliss of believers. ‘They shall hunger no more, neither thirst any more; neither shall the sun fall upon them, nor any heat; for the Lamb that is in the midst of the throne shall be their shepherd and shall lead them to life’s springs of water; and God shall wipe away every tear out of their eyes’ (7: 16, 17). This is a picture of the entire Church triumphant, gathered out of all the nations and thus, in its entirety, standing before the throne and before the Lamb, an ideal which is not realized until the day of the great consummation. We have again spanned the entire gospel age. 3. The seven trumpets (8: 1–11: 19) The next section consists of chapters 8–11. Its central theme is the seven trumpets that affect the world. What happens to the Church is described in chapters 10 and 11 (the angel with the little book, the two witnesses). Also at the close of this section there is a very clear reference to the final judgment. The dominion over the world became the dominion of our Lord, and of his Christ: and he shall reign for ever and ever.’ ‘… And the nations were wroth, and thy wrath came, and the time of the dead to be judged…’ (11: 15, 18). Having reached the end of the dispensation, the vision ends. 4. The persecuting dragon (12: 1–14: 20) This brings us to chapters 12–14: the woman and the Manchild persecuted by the dragon and his helpers. This section also covers the entire dispensation. It begins with a very clear reference to the birth of the Saviour (12: 5)…This section, too, closes with a stirring description of Christ’s second coming in judgment. ‘And I saw, and behold, a white cloud; and on the cloud I saw one sitting like unto a son of man, having on his head a golden crown, and in his hand a sharp sickle…. And he that sat on the cloud cast his sickle upon the earth; and the earth was reaped’ (14: 14, 16). 5. The seven bowls (15: 1–16: 21) The next section comprises chapters 15 and 16 and describes the bowls of wrath. Here, too, we have a very clear reference to the final judgment and events that will take place in connection with it. Thus we read in 16: 20, ‘And every island fled away, and the mountains were not found.’ 6. The fall of Babylon (17: 1–19: 21) Next comes a very vivid description of the fall of Babylon and the punishment inflicted upon the beast and the false prophet. Notice the picture of Christ’s coming unto judgment (19: 11 ff.). ‘And I saw the heaven opened; and behold, a white horse, and he that sat thereon called Faithful and True; and in righteousness he judges and does battle….’ 7. The great consummation (20: 1–22: 21) This brings us to the final section, chapters 20–22, for Revelation 20: 1 definitely begins a new section and introduces a new subject.  This new subject is the devil’s doom. A comparison, moreover, with chapter 12 reveals the fact that at the beginning of chapter 20 we are once more standing on the threshold of the new dispensation. While in 12: 9 we are told that in connection with Christ’s ascension and coronation the devil is cast down , here in 20: 2, 3 we read that he is bound for a thousand years after being cast into the abyss. The thousand years are followed by the little season during which Satan is loosed out of his prison (20: 7). This, in turn, is followed by a description of the final overthrow of Satan in connection with Christ’s coming in judgment (20: 10, 11 ff.). At this coming the present universe, fleeing away, makes room for the new heaven and earth, the new Jerusalem (20: 11 ff.). A careful reading of the book of Revelation has made it clear that the book consists of seven sections, and that these seven sections run parallel to one another. Each of them spans the entire dispensation from the first to the second coming of Christ. This period is viewed now from one aspect, now from another. ..There is another line of reasoning which confirms our position that each of the seven sections extends from the beginning to the end of the new dispensation and that the seven run parallel to one another.  Different sections ascribe the same duration to the period described. According to the third cycle (chapters 8–11) the main period here described is one of forty- two months (11: 2), or twelve hundred and sixty days (11: 3). Now, it is a remarkable fact that we find that same period of time in the next section (chapters 12–14), namely, twelve hundred and sixty days (12: 6), or a time and times and half a time (3½ years) (12: 14). The three designations— forty- two months, twelve hundred and sixty days, time and times and half a time— are exactly equivalent. So the section on the trumpets (chapters 8–11) must run parallel with that which describes the battle between Christ and the dragon (chapters 12–14). A careful study of chapter 20 will reveal that this chapter describes a period which is synchronous with that of chapter 12. Therefore by this method of reasoning, parallelism is vindicated. Each section gives us a description of the entire gospel age, from the first to the second coming of Christ, and is rooted in Israel’s history under the old dispensation to which there are frequent references.” (William Hendriksen, More Than Conquerors: An Interpretation Of The Book Of Revelation, 16-19 (Kindle Edition); Grand Rapids, Michigan; Baker Books)
This use of parallelism which John uses draws directly from the Book of Daniel. In Daniel chapters 2 and 7, the Prophet describes the same four kingdoms in different imagery (I.e., Babylon, Medes/Persians, Greece, and Rome) while explaining the coming kingdom of God (Daniel 2:44; 7:13-14). In each vision, parallels are clearly seen; yet they each produce different details about the various kingdoms under consideration.
The two beasts of Revelation 13 are found in this context of the increasing power of Satan in the world, before the Second Coming of Christ. The mark of the beast is thus seen from the vantage point of those who are the people of the beast (those who take the mark), in opposition to those who are faithful to the Lamb.
The grace of the Lord Jesus Christ, and the love of God, and the communion of the Holy Spirit, be with you all. Amen.