Revelation 17:4-6 (KJV)
4 And the woman was arrayed in purple and scarlet colour, and decked with gold and precious stones and pearls, having a golden cup in her hand full of abominations and filthiness of her fornication:
5 And upon her forehead was a name written, Mystery, Babylon The Great, The Mother Of Harlots And Abominations Of The Earth.
6 And I saw the woman drunken with the blood of the saints, and with the blood of the martyrs of Jesus: and when I saw her, I wondered with great admiration.
Babylon The Great Is Fallen
As you can see from the warning above, Babylon the great or the Catholic Church is the habitation of devils and foul spirits.