@latein @ArdainianRight @hachi @djsumdog @meowski @mrsaturday >That's what Catholic Christians were - the winning side of an early theological conflict.
The early (Catholic*) Church was literally all of Christendom. When that stopped being the case is a point of contention, as is when the institution known today as the Catholic Church came into being, but neither of those points matter in context of the early church.

>What constitutes heresy is entirely subjective and depends on the current Christian group you believe is true, appealing to it doesn't help.
One can take a Sola Scriptura approach and easily make the case against Arius; that's all I've ever done. I do not appeal to the authority of my church, but I choose to submit to its wisdom on matters that are beyond my understanding. It is far to tempting to redefine Christianity, or any other religion, for the convenience of one's own desires. Just look at Sin Chickens and Eruv wires.