First of all, you have to understand who Mystery, Babylon the great is, which is not the church. You won't fine the word church used anymore after the end of chapter 3 and that because Chapter 4:1 is a prophetic allusion to the church being caught up. After this the word ekklesia is never used again until chapter 22:16.
God gives us clues in His word as to who Mystery, Babylon the great is:
* The seven heads are seven mountains on which the woman sits.
Rome was literally built on and is famous for her seven hills
* The woman you saw is the great city that rules over the kings of the earth.
At the time that John was receiving this information Rome was that city that ruled over the kings of the earth
* The woman was dressed in purple and scarlet, and adorned with gold and precious stones and pearls.
Purple and scarlet are the exact colors word by the bishops and cardinals of Roman Catholicism
View attachment 216169
View attachment 216170
View attachment 216171
The woman who rides the beast aka Mystery, Babylon the great, is the Roman Catholic church.
The reference to "come out of her my people" is God calling those who belong to Him to come out from this false religious system before He has the beast and the ten kings destroy her with fire so that no once can ever inhabit that city again.
Once the antichrist/beast is revealed, he will empower the office of the pope and the Roman Catholic church with the power that she has desired. The office of the pope believes that every human should come under his authority and belong to the RCC. Anyone who doesn't will be a heretic to them.
Babylon the great is hiding in plain sight and is advertising who she really is with that Idolatrous Egyptian Obelisk sitting out in the middle of St. Peter's square.
They have and are deceiving over 1.2 billion people by looking Christian. All one has to do a cursory look at what she is teaching to see that she is a counterfeit