[Elsie]

Opponents of the Mormon Church are called “anti-Mormons” because, that is an accurate description. According to the dictionary, “anti” is an adjective meaning “opposed.” You are “opposed,” to the Mormon Church, aren’t you? There is nothing pejorative about the expression; rather, it is an accurate description.

Using that logic then...

Opponents of the Orthodox Christian Church are called “anti-Christians” because, that is an accurate description. According to the dictionary, “anti” is an adjective meaning “opposed.” You are “opposed,” to the 'other' Christian Churchs, aren’t you?

Therefore being Anti-Christ would fit quite well; wouldn't it??

[ComeUpHigher]

See post 844. It wouldn’t be accurate, would it?

[Truth-Miner]

If Anti-Mormon is correct then Anti-Othrodox Christian would be correct. To shorten it to anti-Christian or anti-Christ would be disingenuous and only used to further your own opinion.
For example could I call you anti-patriot because you opposed the P.a.t.r.i.o.t bill?
So to call a Mormon an anti-Christ is bad form. They have repeatedly stated they are not against Christ, just against your interpretation.