Are You a Heretic? part 2
The author at the Christian Apologetics and Research Ministry points out that the heresies he lists are to him essential ones, ie the "serious assaults upon the character of God, of Christ, and salvation itself" (and they appear to be the ones in the quiz). Unhelpfully, he doesn't describe the process of determining which teachings are heresies, and blithely excuses the horrific persecutions of heretics.
An in-depth study of one heresy should be instructive, so I studied the Donatist Heresy, my results from the quiz. Funny thing, Wikipedia's take on the topic is radically different from Catholic Answers'. In any case, the church decided that even if a priest makes a grave sin, say repudiating his faith, he may still officiate over the sacraments (ie sole moral authority lies with the church). Donatists wanted priests who did the right thing. When it was apparent that this idea had a lot of traction by the number of Donatist churches, it was firmly dealt with and the Donatists are no more.
A story of Christians killing Christians, to keep the money and power within one group. Why does the church think it has the high moral road, again?