Revelation is a hard book to understand but it is mostly telling what will and is happening in the last days. The Babylon talked about could be the USA and /or the church of Rome. The bible is based mostly around the Jewish nation of Israel, they are God's chosen people to deliver the Gospel to the world, but they failed to do so, that is why God blinded them spiritually, they are still looking for their Messiah, which is Jesus but they didn't recognize Him and had Him crucified, but He rose three days later, He will be returning when the time is right, which is about now. Jesus told the signs to watch for when He would be returning, those signs are happening now.