Historically, some Christians have (wrongly) believed that Babylon was a godly, pure church that apostatized, which apostasy was its fall. This belief would mean that the 2nd angel of Revelation has already happened.
This study will show that belief is wrong on many levels. These mistakes were less important previously than now, when we are looking for and getting closer to the fulfillment of Revelation 14, the three angel's messages and the return of our King.