No matter who you are, you're a heretic to somebody.
Heresy support group, anyone? "My name is Larry, and I'm a heretic." "Hi, Larry!!!"
Christianity is a heresy of Judaism.
Judism is a heresy of the Earth Mother-Sky Father religion.
Or, if you prefer, there were no heresies until the council of Nicea defined Orthodoxy, and Christianity became the state religion of the Roman Empire.
"...Then, during the third reconciliation of the last of the McKetrick supplicants, they chose a new form for him: that of a giant Slor! Many Shuvs and Zuuls knew what it was to be roasted in the depths of the Slor that day, I can tell you!"
I agree. I think it would be interesting where the three main branches of Christianity agree on heresy (most likely the first four centuries) as well as where they disagree and why.