This is an interesting topic not only for purely historical study but also because it illustrates so many of the issues today. There were numerous sects that emerged after 1000 AD some leaning more towards Gnosticism perhaps direct descendants and some more in line with various Protestant movements of later centuries. A list:
Gnostic: Cathari, Albigensian, bogomils, henricians, paulicians, Manichaeans and a panoply of earlier sects.
More Protestant: waldensians, petrobrusians, Lollards, Hussites
This is a discussion thread: you can discuss these sects in their historical context or how their ideas and the struggles the church and these sects had. This can be compared to modern intractable conflicts between Protestants and Catholics and with regards to Catholics and Gnostics/Manichaeans/New agers/ Neopagans etc…
With specific focus on catholic vs Protestant/pre-Protestant if Rome is truly Christ’s bride why have so many left Her with nothing but vile to say regards to her and why have so many even before 361 AD protested against her? In conclusion who is God leading to victory? Are the anti-catholic Protestants right and Rome is the pit of abominations or is church right that she is a faithful virgin to her husband and those who condemn her condemn her husband? This isn’t the question the question is who will God vindicate? And who will he chastise?