The thirteenth chapter of Revelation introduces two new characters into the story of Revelation 12, a beast from the sea (13:1-7) and a beast from the earth (13:11). After their introductions, both beasts play a major role in the final crisis of earth’s history. Together with the dragon, the opponents of God and His people number three. The number three is associated with the godhead in chapter one and with Babylon in chapter 16 (verse 19). So this grouping of three functions as a “counterfeit trinity” in chapter 13.
The relationship between chapters 12 and 13 is clarified when one takes the time to look at a textual issue at the intersection between the chapters. The King James Version opens the chapter with John standing on the sands of the sea (Greek: estathên—“I stood”), while most newer versions tell us that the dragon, the subject of Rev, 12:17, stood (Greek: estathê—“he stood”: ESV, NASB, NIV, RSV, NRSV) there. The Greek manuscripts of Revelation are divided on this reading, but the earliest and most reliable manuscripts and the early translations read “he stood,” referring to the dragon.
This reading better connects Rev. 12:17 with the story of Rev. 13, where the dragon calls up allies from the sea and the land to assist him in the final conflict. That means that the calling up of the two beasts in chapter 13 is the way that the dragon wages war against the remnant of 12:17. Chapter 14, then, elaborates on the remnant’s response to the dragon’s attacks. Read in this way, Revelation 12:17 offers the final battle in a summary nutshell, followed by elaboration on the two key characters in the nutshell summary, the dragon (elaborated in chapter 13) and the remnant (elaborated in chapter 14). The final battle is further elaborated in chapters 15-19.