6 Then I saw that the woman was drunk on the blood of the saints and on the blood of the witnesses to Jesus. When I saw her, I was greatly astonished.
John was shown that the woman (the false church) was responsible for the deaths of the true followers of Jesus Christ and he was amazed by how that church had so much power.
7 Then the angel said to me, “Why are you astonished? I will tell you the secret meaning of the woman and of the beast, with the seven heads and the 10 horns, that carries her.”
As John was mesmerized by the vision of the woman, the angel questioned his astonishment by practically saying, wait until I reveal to you who is the one behind this false system by which is deriving its power from.
8 The beast that you saw was, and is not, and is about to come up from the abyss and go to destruction. Those who live on the earth whose names have not been written in the book of life from the foundation of the world will be astonished when they see the beast that was, and is not, and will be present again.
“The beast that you saw was, and is not, and is about to come up from the abyss” – The beast that the angel is mentioning was seen back in Revelation 11:7. This beast comes from the abyss just like the king of the locusts who is seen in Revelation 9. Either this beast is in reference to Abaddon in Hebrew and in Greek Apollyon or to the Antichrist, it is not clear. What is clear, it will be a high ranking demon.
“Those who live on the earth whose names have not been written in the book of life” – If you notice that those who are dumbfounded and impressed by the beast are the ones who have rejected Christ and do not have their names written in the Lamb’s Book of Life which indicates that they are highly prone to deception.
9 “Here is the mind with wisdom: The seven heads are seven mountains on which the woman is seated.
This false church (the woman) is in a city that is surrounded by seven mountains.
10 They are also seven kings: Five have fallen, one is, the other has not yet come, and when he comes, he must remain for a little while.
The seven heads have two meanings, 7 mountains (verse 9), and 7 kings which means, five kings have died, the sixth king is ruling, probably in John’s time, and the seventh is a future one to come. The Antichrist will succeed the seventh (verse 11).
The only city who claims to be Christian and is situated by seven mountains is the Vatican city in Rome.