Why does the LDS Church reject the historic church’s concept of the Trinity? Not only does the Trinity remove any hope of a Mormon ever achieving godhood, but it also undermines Smith’s First Vision account and subsequent teachings regarding a multiplicity of deities. If it can be demonstrated that the Father, Son, and Holy Ghost/Spirit are God, and at the same time be shown that there exists only one God, it would definitely place the integrity of the first Mormon prophet on the line.
Bill McKeever and Eric Johnson, “Mormonism 101,” pg.66