Yes, they're called sects/denominations
All religions have these with significant differences. Catholics and Protestants (that's probably the term OP is looking for, it describes all branches of christianity that are not Catholicism) are the only ones who think it makes them a different religion entirely
And even then, that's not concrete that they consider themselves seperate.
After all, you have Greek Orthodox Christians who are also quite close to Roman Catholics.
And then you have the Anglican Church (Church of England) who are Protestants, but do identify as being Catholic (albeit not Roman Catholic) and Reformed.
If anything, the one defining feature of being a Christian religion is believing that Jesus of Nazareth was the Son of God. This at most seperates you from Judaism, where you don't believe Jesus was the Son of God, and Islam, where you do believe he was the Messiah, and a prophet but not the Son/embodiment of God, and it seperates you from the 'Eastern' religions, such as Hinduism where Jesus isn't involved at all.
That throws in some tricky situations though, where other large churches come into play, such as the Mormons. They too believe Jesus was the Son of God, but their religious beliefs are vastly different from any traditional Western christian religion.
I would probably identify as Agnostic.
As far as I am concerned there is no concrete evidence that God (or a god) does or does not exist.
If there were to be evidence that would definitively prove the existence or non-existence of God then I would either be theist or atheist. But the only concrete proof that there could be, would most likely be some evidence of what caused the Big Bang.
Did it occur on it's own, or did a higher being cause it.
There's no point in saying yes/no to the existence of God while I can't prove it, in my opinion.
If I were to get into arguments and vehemently defend one side or the other, I would see it as wrong, since I can't ever truly prove one way or another. And it's a rather big thing to argue for/against without knowing for certain.
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