Ever the contrarian, I have to say I am afraid that you are right. We are teaching people a bad thing by forcing every issue to be considered in denominational lenses. It may be accurate, but the precision is all off.
I am not arguing that people shouldn't clarify denominational constraints (it does make a question better generally), but I'm of the opinion we should be a little bit more forgiving then we are.
There is this feeling that Christianity is SO broad, that there is nothing we agree on. Using this site's definition, the statement may perhaps be accurate, but it is too imprecise to be of much use. Let me take, for example, a few core doctrines:
- The Trinity
- That Divinity of Jesus
- The Fact that God exists at all
- The Fact that God is One, and there are no other Gods before Him
These are some pretty basic things. I can find exceptions to each one of the above.
- The Trinity: Unitarians, Mormons, and non-Nicenes.
- That Divinity of Jesus: Unitarians, Jehovah's Witness
- The Fact that God exists at all: Christian Atheists
- The Fact that God is One, and there are no other Gods before Him: Jehovah's Witness.
So, it is "accurate" in that the statement has edge cases that push the boundaries. But it is way too imprecise. I'd argue that 98% is almost as good as 100%. I can pretty well tell that just about every Christian does believe these things - even if as an expert I am aware of the asterix that says "*plus or minus a very small fringe."
At face value, people would think: "What? Christians don't believe that God exists?" Well, if you include the 0.000000000002% of the population that calls itself Christian Atheist, yes. And, are Mormons irrelevant? No - but in the grand scheme of things, there are probably about 15 million Mormons worldwide, in a sea of more than 2.2 billion Christians. Even if you add in the Jehovah's Witness, the Coptics, and pretty much EVERY non-Nicene Christian, you're still talking well less than 2%
And then again, for comparison, you can find more than 2% human beings that believe:
- The Holocaust never happened
- We didn't land on the moon
- 9/11 was inside job
- Justin Bieber is the greatest singer of all time.
So, is it fair to say that there isn't a unanimity of belief that "the Holocaust didn't exist?"
With the possible exception of Justin Bieber (Ali, I know you love him!) I don't think it is fair to say that based on the above, that "people don't believe in the holocaust, the moon landing, or that 9/11 wasn't the result of terrorists." The imprecision does not account for the vast, vast majority that is in agreement.
I have argued before in What is "mainstream Christianity"? that when most people think "Christian" it is misleading to assume anything other than Nicene Christianity. I am not arguing that non-Nicene Christianity should be off-topic, but I do believe that it is not up to every passerby to know the difference.
Absent any other qualification, I think it is fair to say that any question asking about "Christianity" means "Nicene Christianity," but that Non-Nicene forms are not off-topic in answers, if labelled as such.
And, going back to the question, I would argue that teaching everyone to look through a denominational lens distorts the unity of the Nicene Church.
Are there distinctives in each denomination? To be sure. But to claim there is no unity just ain't so.