Earlier quoted context omitted.
> This is very true, and I can't believe some religions that people think are the same. They happen to use the same words, like "God", "heaven", etc, but the concepts are completely different and incredibly incompatible. What's more, the definitions of the religions themselves are so slippery, we can barely begin to compare religions. For example, suppose we take the author's advice and try to dereference the term "a…
Well, one could call "Christianity" a superset of individual religions that fit within a certain range, and do the comparison off of individual denominations. That has the further advantage of demonstrating how individual denominations within Christianity often themselves have incompatible beliefs.
Theology about the nature of Christ has significantly higher weight. Heresy, etc. This is where you see little diversion between denominations and more diversion between, say, Protestants and the LDS Church.