In Charles Taze Russell's time he said the "papal system is Babylon the Great.
One Christian religion or church pointing to another Christian religion doesn't make much sense. Not when you have blatant non-Christian religions out there.
Babulylon the Great as the book of Revelation says is an end time capital of the New World Order. As Babylon of old that was deeply religious so it will be the Babylon the Great. Think of it as Rome the city controlling all kings of Europe in the Middle Ages.
Deeply religious yes, but which religion? It can't be a Christian church (it has to be an antichristian religion). Not to say that demonic practices are not uncommon amongst even members of Christian churches. I knew people who did tarot 'for fun' in the episcopal church I visited. There are catholics that do yoga. But this is why God says to Christians 'get out of her if you don't want share her fate' referring to Babylon the great and her spiritual practices. Meaning, Babylon the great is not a Christian church.