Another difference for heresy is that it is considered the result of thinking differently to an established norm. Although it's traditionally had more serious repercussions when deviating from a religious standard, the term applies to other disciplines as well.
Orthodox:
adjective
1. Adhering to the accepted or traditional and established faith, especially in religion.
2. Adhering to the Christian faith as expressed in the early Christian ecumenical creeds.
from Greek: right + opinion
Heterodox
adjective
1. Not in agreement with accepted beliefs, especially in church doctrine or dogma.
2. Holding unorthodox opinions.
from Greek: different + opinion
I am a seeker of truth with strong roots in Christianity, and am exploring the basic tenants of the major religions. I have an interest in the pagan roots of the Catholic religion too.
Best wishes in your studies; how religious thinking has shaped -- and been shaped by -- each culture is quite a story. I do have to smile a bit at that second sentence; I still remember a few classmates who were, if you'll pardon the pun, hell-bent on "converting" Catholics to Christianity. (It smacks of a teenage garage band singer lecturing Luciano Pavarotti on music theory.) The Reformation was a desperately needed correction to break the ossifying, dominating Roman monopoly on every aspect of the Western world. At the same time, that early, heretical Jewish cult called Christians would not have survived, let alone
become a dominant force, if not for the Classical institutions that shaped and then promulgated it.
Now for some wordplay to close this post: "Not Under Hamartial Law."