In The Book Of Revelation, What Did John Mean By “MYSTERY BABYLON THE GREAT” And “THE MOTHER OF HARLOTS”?

Haven't you ever been curious to understand what this "Mystery" is, and who this "Harlot" is?  And for crying out loud, WHY ARE THESE WORDS WRITTEN IN ALL CAPS IN REVELATION 17???, as written here: Rev. 17:5--"And upon her forehead was a name written, MYSTERY, BABYLON THE GREAT, THE MOTHER OF HARLOTS AND THE ABOMINATIONS … Continue reading In The Book Of Revelation, What Did John Mean By “MYSTERY BABYLON THE GREAT” And “THE MOTHER OF HARLOTS”?