Translation:Protestantism and Orthodoxy are two Christian religions.
I think it would be better to say they are two christian denominations (χριστιανικά δόγματα).
Hi! We haven't taught the word δόγμα/δόγματα and therefore we cannot add this sentence.
No, they aren't different religions, but different forms of Christianity according the Wikipedia, https://en.m.wikipedia.org/wiki/Eastern_Orthodox_Church and https://en.m.wikipedia.org/wiki/Protestantism . I think it is a non-biased term that doesn't not uses the term "heresy", as this term is so much charged, from the Ancient verb αίρω, a different dogma, that separated from the mainstream. https://el.m.wiktionary.org/wiki/αίρεση