You will probably find this offensive, batchman555, but your quotation of the Book of Revelation belies the fact that you completely misunderstand the book. It was not written for the general public, like yourself. Originally, Christianity was one of many competing Mystery Schools of the day. Other ones were the Eleusinian Mysteries, the Hermetic Mysteries, the Mithraic Mysteries. The Apocalypse actually describes initation into the christian mysteries. It has absolutely nothing to do with any kind of prediction for the future. The symbolic content of the Apocalypse parallels other mystery symbolism of other ancient mystery teachings.
Needless to say, you cannot scare me with any message to Sardis, when, in fact, Sardis is located in my very own throat. And yours. The language symbolizing the cities and their messages is a set of allegories or metaphors. The Cities and "Seven Spirits" are specific nerve plexuses that the ancients realized played a role in spiritual awakening. The city of Sardis was meant to symbolize what Hindus called the Visshudi or Throat Chakra. A set of nerve plexi that had specific mystical applications.
By the way, I'm am completely familiar with the bogus interpretation of old Armstrongism related to the so-called "seven church eras." It's entirely false. No wonder since the man was entirely uneducated to begin with.