Please muslims answer...?

well the guy shouldn't have gone that far as saying that shia muslims don't count as muslims because that's referring to all shia muslims and only Allah is the one to judge who is a true believer and who is not. but it is a great sin to change the context of the quran. and why would anyone change the context of the quran? it is Allah's words and so no change needs to be made to it. i don't judge anyone like that. and i'm not a sunni, shia, or part of any sect. i'm just a muslim.