God... Truth or fiction?

And why are Catholic and Christian listed as separate items? Christians come in three varieties: Catholics, Protestants, and Orthodox. Moreover, Orthodox is the smallest branch.
For example, I am a Protestant Christian.

If we are going to differentiate between different Christians, then
1) we need to divide Protestants, as Lutherans and Calvinists are quite different things, in my opinion, and there are even more branches. Also, there are ancient Eastern churches.
2) we need to divide Muslims. Yes, and maybe not just them.
In short, it would be easier to put everything in one category and not bother.