If McConkies statement were a Venn diagram I would interpret him as saying that the circle labeled Mormonism and the circle labeled Christianity were equal and coextensive  That differs from the most common Mormon perspective which says that Mormonism is a subset of Christianitythat is that Mormonism circle is entirely enclosed by the Christianity circle  Other possible nonMormon views might be that the two circles partially intersectthat is that some of Mormonism is Christianity but some of it isntor that the circles are nonintersecting and separatethat is that Mormonism is entirely outside of Christianity   I do agree that the intro needs a bit of shortening and that there are redundancies that need to be removed I might take a crack at it if I have time or someone else can take a stab