What are some major heresies taught/promoted by the chosen? I've generally liked the show (again, I'm not watching for an education in theology) and other than Mary briefly mentioning that she experienced pain giving birth to Jesus, I haven't noticed, off the top of my head, anything I'd say is heretical. Historically/culturally inaccurate in some cases, sure.
After seeing the trailer for season 4, I am a little concerned based on one line but I'll just need to wait and see the context it's used in.