"'I don't know what you mean by 'glory,' Alice said.
Humpty Dumpty smiled contemptuously. 'Of course you don't—till I tell you. I meant 'there's a nice knock-down argument for you!'
'But 'glory' doesn't mean 'a nice knock-down argument',' Alice objected.
'When I use a word,' Humpty Dumpty said, in rather a scornful tone, 'it means just what I choose it to mean—neither more nor less.'
'The question is,' said Alice, 'whether you can make words mean so many different things.'
'The question is," said Humpty Dumpty, "which is to be master that's all'" -Lewis Carroll, Through the Looking-Glass
(Raleigh, NC: Hayes Barton Press, 1872), p. 72.
Wittgenstein held that the meaning of a word is its use. Trending today in contemporary academia regarding the word "Christianity" is, using Bart Ehrman as an example, the affirmation that anyone claiming to be a Christian was/is a Christian no matter what the particulars (literally almost anything goes) as I detailed in the following blog article from which I'll provide a brief excerpt for the purpose of illustration, after which I'll turn to Mormonism.
For Ehrman Christianity includes Gnosticism, Docetism, polytheism (ibid, p. 2), Ebionitism (ibid, pp. 99ff.), Marcionism (ibid, p. 103ff), Galatian Judaizers, Colossian angel worshipers, and the antinomian (lawless) libertines described in the epistle of James and the book of Revelation (ibid, p. 177). Even the false teachers castigated by Jude and 2 Peter are specifically called Christian by Ehrman, even though, as Ehrman admits, we don’t even know who they were or what they said (ibid). Here is the heart of Ehrman’s concept of what “Christian” means. It can mean anything, but actually means nothing at all.
All these groups are described by Ehrman as a part of early Christian diversity. Why? “I cannot emphasize enough that all of these opponents in all of these communities identify themselves as followers of Christ… what would all these groups of Christians have to say for themselves?” (ibid, p. 177). Ehrman seems to believe that anyone claiming a label deserves the benefit of doubt about it merely because they claim it. On this assumption, if Humpty Dumpty claims to be the legitimate Queen of England, we should believe him. Of course this presupposes that we know something about who or what the real Queen of England is supposed to be. If the antinomian (morally nihilistic) libertines cited by James and the book of Revelation claim to be Christians, who are we to deny it? (ibid, p.177). If Jewish mystics at Colossae who worshipped angels claim the label “Christian,” who are we to deny they were really Christians? (ibid, p.177).
If the reader will momentarily indulge the unmitigated audacity of the present author in using the phrase authentic Christianity as if there might actually be such a thing, in point of fact, if we don't deny antinomians and angel-worshippers were a part of authentic Christianity we are in fact no better “scholars” than Humpty Dumpty is the Queen of England, whether we teach at Chapel Hill or not. Why? Because even on the most radical historical critical assumptions we can find, it is quite undeniable that Jesus and his disciples were monotheistic Jews 
 cf. L. W. Hurtado, One God, One Lord: Early Christian Devotion and Ancient Jewish Monotheism (Philadelphia: Fortress, 1988). Virtually all modern scholars acknowledge that Jesus and his disciples were traditional Jews (Ehrman, op cit, p. 96), which in and of itself is a major paradigm shift in biblical scholarship since, after the defeat of Hitler, anti-Semitic German Biblical scholarship (it was often overtly so from the 19th to the mid 20th century) which sought vigorously to minimize the influence of Judaism upon Christianity and to maximize the influence of Hellenism (Indo-European/Aryan), has been largely eclipsed. Today denial of the essential Jewish character of Jesus and his disciples is virtually unheard of. Ideology has often co-opted historical-critical scholarship from its inception to the present day.
Monotheistic Jews do not worship angels. Angel worshipers, then, cannot legitimately figure in, as Ehrman calls it, “A Modern Assessment of Early Christian Diversity” (at least not a good one). Another inextricable feature of both the historical Jesus and Primitive Christian message within the first decade of Christianity (the kerygma) is the ubiquitous call for repentance (see Colin Brown, ed., Dictionary of New Testament Theology, vol. 1, pp.353-362). Repentance is a turning away from sin and to God; antinomianism and libertinism are the precise opposite of this. If so, it would seem that no scholar worthy of the name could possibly affirm antinomianism and libertinism have any reasonable claim to be a part of “Early Christian Diversity,” yet that is precisely what Ehrman does affirm (op cit, p. 177). http://katachriston.wordpress.com/2010/12/27/bart-ehrmans-lost-christianities-a-critique-part-1/
No doubt those who would not hesitate to call Mormonism "Christianity" are legion today despite its denial of monotheism, despite ideas like the doctrine that God the father had his own father, who had his own father, and so on, or ideas such as God the father having been once was just like we are now before evolving into his godhood, despite its notion that Jesus over time similarly grew into being God, and etc.
If someone sympathizes with views like Ehrman's, they will have no problem calling Mormonism Christian. Personally I just cannot countenance the notion that any religion which denies monotheism as Mormonism does, is "Christian" in the traditional sense of considering Christianity to be a monotheistic religion ...call me old-fashioned.
Hec, I'll go out on a real limb and say any religion that denies the Nicene Creed (as Mormonism does) is not Christian!. That's *really* old-fashioned!
St. Nicholas punching Arius in the face at Nicea, circa AD 325. "Those were the days when girls were girls and men were men..."