"I guess I'm not sure why you would have to feel offended if someone holds a perspective that you don't find particularly accurate. If you want to argue accuracy from a theological stand point, that's fine. But I don't see how getting offended over it serves any purpose.
My point was not to argue theology (I already said I'm not a theologian), but it was to give a slightly different perspective for the OP. Let me see if I can put into written words why I think this "religion of Jesus" perspective resonates with me. I think that what happens in religion (generally speaking) is that people get into theological arguments that, in the long run, don't really help them to be better people or to develop a more meaningful spiritual practice. The winners of such debates get to declare the losers heretics, and I don't really think this benefits anyone. So when I say the "religion about Jesus" that's what I'm talking about. I think when people get into arguments like, "you're not a ___fill in the blank___ because you don't profess to believe xyz" I think that that kind of position is really missing the boat. I think the bigger picture is, does my spirituality and my practice help me to be a more whole person and does it help other people to be more whole as well. The point of it all is that I don't think it makes a person "more Christian" to sit around and argue about the accuracy of their spiritual and/or theological understanding of the person of Jesus. I think that doing so is missing the point of what Jesus was trying to teach.
I think that if someone (like the OP) wants to identify themselves as a Christian because they want to follow the example of Jesus' life, then I don't see why that should be a problem to anyone else. If following Jesus' example helps a person to be more spiritually whole and helps them to be a better person, then what, exactly, is the point of trying to argue with that person that they aren't a Christian b/c they don't believe xyz? (not a rhetorical question)"
So what do you think Jesus was trying to teach? The only way to determine that is through... drum roll... theological debate. There's a difference between spending endless hours nitpicking over some tiny, inconsequential point of doctrine when your neighbor lies bleeding at the door, and hashing out some extremely basic issues such as "Who was Jesus?", "Do I believe what He was trying to teach?", "What was He trying to teach?" and so on. Theology isn't some evil ivory-tower abstraction designed to foster division and hinder good deeds; it's a way to get closer to God. You can't get close to a lover or child without knowing about him - his likes and dislikes, his background, who he is, what he does, his interests and passions and plans; theology is just the same, only it's learning about God rather than a human.
Your post presents a theological perspective as much as anyone's; I just don't think it's very well-informed, Scripturally speaking. The point of Christianity is not to make people nicer or better people, to make them "spiritually whole", whatever that means, or to develop a "meaningful spiritual practice" (again, whatever that means - the phrases require theological definition). I do find those points of view offensive - intellectually offensive, if you will - because if you're going to comment on someone else's religion, you ought to attempt to understand what its texts teach, what the self-defined "point" or purpose of the religion is, and so on. You can cherry-pick bits of the more generic Christian philosophies or sayings, the ones that fit in with your pre-existing worldview, but that isn't doing justice (or showing respect) to the religion or the texts. Christianity requires a radical upheaval of one's worldview; it isn't supposed to neatly slot into Day 6 of Becoming a Better Person, along with yoga and volunteering. That's totally missing the point. And if one claims to be a fan of Jesus, it seems only fair to let His words and actions dictate what HE felt the main thrust of his life and teachings was. Calling him a social activist or humanitarian or whatever is, to use my earlier analogy, like calling Martin Luther a marriage reformer. Being a fan of Luther's teachings about marriage doesn't make you a Lutheran, and being a fan of Jesus' teachings about compassion or charity does not mean you are "following the religion of Jesus" - not the way JESUS defined it, anyway! Now, the OP could certainly legitimately say "My spiritual beliefs are.... XYZ... and I follow some of Jesus' ethical principles", and that would be fine. But to call oneself a fan or follower or disciple of a person generally means that you agree with their main message or worldview - if you say you're a fan of Martin Luther King, people will assume you're talking about his views on racial equality. If it turned out you disagreed with those views, don't believe he really said any of that stuff or whatever, and you just like like some comments he made one time about baseball, it would seem very odd and misleading to call yourself a Martin Luther King fan. At best, you'll confuse people, and at worst it will be seen as disingenuous or deceptive.
Of course, if you want to make the case that Martin Luther King WAS primarily a baseball fan and should be defined as such, that's cool; but you'd have to go from his speeches and transcripts and letters and so on, ie. what he actually said.
As for being offended, well, I'm not sure it usually "serves a purpose", but is that the point? It doesn't really "serve a purpose" to be upset by racial slurs or sexist jokes, but people still are. And people get offended by factual inaccuracies all the time - "mothers who breastfeed past six months are sexually deviant", anyone? I would indeed find it offensive - not to the point of foaming at the mouth or anything, but sort of wryly amused and a bit disgusted - if someone told me that by loving her neighbor and giving to the poor she was following the "religion of Jesus", and I was therefore following the (presumably adulterated and spiritually inferior) "religion about Jesus". At the least, she would have to back that statement up with some damn good scholarship, not just claim she wasn't a theologian and didn't want to defend the statement.
"If following Jesus' example helps a person to be more spiritually whole and helps them to be a better person, then what, exactly, is the point of trying to argue with that person that they aren't a Christian b/c they don't believe xyz? (not a rhetorical question)"
Sorry, just noticed this. Well, the point is, according to most Christians (including me) if they are not truly saved, they will spend an eternity in hell, and having been a "better person" won't have done them one jot of good - because the entry requirement for heaven, if Jesus isn't standing in for you, is NOT "better" - it's "perfect", and that's impossible for sinful humans to attain by their own power. THAT was Jesus' message - "believe in me for salvation" - not "be spiritually whole and do good things". Rather a striking difference, really. :)