In the same vein - when we look at the Gospels we can see differences. Three are grouped together to form what is known as the synoptics(Mt, Mk, Lk) and then there is John. They are all a little different, John being mroe different than the others, because they were written to different communities. Does this imply that Jesus founded several different churches? No, it just means that there are different facets of the one belief. There is the Catholic Church and then there are different rites of the Catholic Church. Roman, Byzantine, etc… It is the smae in Revelations. Your friend is taking aliteral perspective instead of taking the text as it is intended, as apocalyptic literature. What he/she is doing is essentially trying to read a poem like a newspaper. The end result is you miss the message! If your friend gives you any greif over that, jsut ask him/her if they read song of songs, a gospel, and genesis all the same way. If he/she says yes, I highly reccomend further theological discusions with him/her and just be a witness to the Truth. After all, Preach the Gosepl Everywhere, if necessary - use words(St. Francis of Asissi.)
Pax