So, in your view, one Church became a different Church??? As Paul says in Eph 4:5, there is "one Lord, one faith, one baptism". And there has always been only one Church: Et unam, sanctam, catholicam et apostolicam ecclesiam (one, holy, catholic and apostolic church). It does not make any sense to say that one Church became another Church. Did Christ have one body, and then get another body?
That is absurd. There has only been one Church, and it has extended throughout time since the day of Pentecost. The gates of hell have not prevailed against it, ever. Nor shall they. The Church never ceased to exist, and then re-appeared later. It has existed in unbroken, organic unity from the beginning.
-A8
You know what we believe. That the Church through all time has consisted of all Christian believers (the Bride of Christ as described in the Bible). The institutional church is another matter. You believe that it has always been the Roman Catholic Church. We don't believe that. Further, I don't believe that this proposition can be proved to the satisfaction of either side, just as no one proves the existence of God. So, no I don't believe that the Church (the Bride of Christ) has changed nor will it change. The institutional church...yes that has changed and it continues to change.