This isn't purely emotional, this is an interest in being clear on the categories by which Christianity identifies its own. The argument is that it's either true or it's not that I can justifiably judge the hearts of these individuals prior to having a lot more information about each of them individually. And it's either true or it's not that when speaking about Christianity we should take the words of Christ seriously, viz., "By their fruits you shall recognize them?" These things make a practical difference as to who we will finally say counts as Christian, and who we will not. You can say I'm not speaking anything of content, but it seems a very simple question: Are not Christ and his disciples capable of determining the marks of true Christians? Or do later believers get to ignore the actual teachings of Christ when claiming to follow him? You haven't answered these questions because, I am guessing, you have not actually thought through them. That they have content is clear from the fact that it makes an important conceptual and practical difference. Either I can claim to be a Christian when killing Jews, or I cannot. Either anti-semitism is consistent with Christianity properly interpreted, or all such interpretations are exegetically flawed. I'm aware the use Luther and others have made of certain passages, but it's far from clear that they did so with textual warrant. When interpreting a text, you take the whole context into consideration. The New Testament writers weren't formalists, and neither should we be.