Revelation 13 showed the first beast, with seven heads and ten horns, who is also the fourth beast of Daniel 7. Revelation 17 tells more about that beast and the woman who rides it. It concerns the Antichrist, who comes in the second half of the seven years, the forty-two months (1,260 days) of his rule.
A woman who is a city
An angel shows John the judgement of the great harlot who sits on many waters. She is not a real woman but a city.
And the woman which thou sawest is that great city, which reigneth over the kings of the earth.
— Revelation 17:18
The seven heads are seven mountains on which the woman sits (Revelation 17:9). Other cities may stand on seven hills, but every other prophecy fits Rome too, so the city is Rome, the seat of the beast.
Elsewhere Scripture pictures cities as women. Ezekiel 23 names two sisters, Aholah and Aholibah, who are Samaria and Jerusalem. They were unfaithful by trading with Assyria and Babylon, taking up their gods and worshipping their idols, as a wife leaves her husband for another. God chose shameful words on purpose, so that they would feel shame.
Rome's unfaithfulness is political. Its emperors held religious and political power. Later the religious power was placed in the hands of the bishop of Rome, and the office of Pope began. The empire's political power ended, but the religious power continued, controlled from Rome. The Pope is also ruler of Vatican City, so governments welcome him as a political leader. A church should be devoted to God, and God blames this one for joining in politics: it has committed adultery with the kings of the earth (Revelation 17:2).
Scarlet, purple and names of blasphemy
The woman sits on a scarlet beast full of names of blasphemy, and she is dressed in purple and scarlet (Revelation 17:3–4). Scarlet was the colour of the Roman army's clothing and shields. The church kept it: those gathered at a Pope's funeral are seen in scarlet, and some ranks wear purple.
The emperors called themselves divine and saviours of the world. The church that followed also claims titles such as Successor of the Prince of the Apostles, Supreme Pontiff of the Universal Church and Pontifex Maximus, and speaks of the power of Peter. In God's sight these are blasphemy. Jesus told the apostles that no one among them was great, and that whoever would be great must serve all, so there is no chief apostle to succeed. The keys given to Peter are not iron keys but the opening of the way of salvation, which Peter did on the fiftieth day, when the Holy Spirit came down and 3,000 repented, were baptised and were saved. And the high priest is Christ alone: we are all brothers.
Babylon, the mother of harlots
And upon her forehead was a name written, Mystery, Babylon the Great, the Mother of Harlots and Abominations of the Earth.
— Revelation 17:5
Babylon means confusion, and some of this church's teaching became confused. Take the teaching about God. It says that the Father, the Son and the Holy Spirit are three, distinct from one another, and that each is God. Up to there the meaning is clear. But it then says that these are not three gods, only one God made of all three. If three distinct persons are each God, that makes three gods; and if three together make one God, each would be a third of God, which is not what is taught either.
Many churches came out of this one, such as the Lutheran, the Methodist and the Baptist, and the same confusion stayed in them. So she is the mother of harlots, and they are her daughters, called harlots too, who share her confusion about God's word. The Bible's own teaching is different, and is for another time.
The beast that was, and is not, and yet is
The woman is drunk with the blood of the saints and of the witnesses of Jesus (Revelation 17:6). Rome persecuted Christians in the early days, and Jesus Himself was put to death by Pilate, Rome's officer. At the end the Antichrist will persecute true believers again. Today's Popes are good men who do not speak against Jesus, but as Satan entered Judas, Satan will enter whoever holds the office then.
The beast was, and is not, and yet is (Revelation 17:8). The empire is gone, but it is present as a church under the Pope. The seven kings are seven great emperors, one after another: when John saw the vision, five had fallen, one reigned and one was still to come (17:9–10). The beast is an eighth, and yet of the seven, because the seventh head's religious power lay with the Pope and its political power with the emperor, together one head. The political power ended, the Pope's office remained, and in the three and a half years Satan will enter whoever holds it.
The ten horns are ten kings (17:12–13): the ten parts of the Roman empire, such as the Anglo-Saxons, Franks, Visigoths, Ostrogoths, Lombards and Alemanni, which are today England, France, Spain, Germany and Italy. They have one mind: they work and decide together as a union, which today is called the European Union. When the covenant is made they give their authority to the beast, for God puts it in their hearts until His words are fulfilled (17:17). The man in the Pope's office gains great authority through that covenant, but does not use it for the first 1,260 days.
The covenant and the temple
Daniel 9:27 says that he makes a covenant with many for one seven, and in the middle of it stops the sacrifice and the offering. There are no sacrifices in Jerusalem now, because there is no temple, so a temple must be built. Perhaps the covenant allows for it; perhaps it is built in the "half hour" while the bride is made ready. When it is built the bride is taken up, and those left on earth begin the sacrifices and offerings, which continue until the 1,260 days end. Then the Antichrist comes and stops them, and his forty-two months begin.
Takeaway
A church's calling is devotion to God, not politics. Christ alone is high priest, and among His people no one is great. Confusion about God's word is what the name Babylon means.