I have addressed and refuted the false but, sadly, popular claim that Latter-day Saint Christology is “Arian”:
In his book comparing and contrasting Latter-day Saint theology and practices with those of Jehovah’s Witnesses (a group that do have an Arian Christology), Alonzo Gaskill wrote:
Latter-day Saints differ with Witnesses on the degree to which Jesus can be classified as God (with a capital G). Like Witnesses, some might call Mormons Arian because they see Jesus as subordinate to the Father. However, unlike Witnesses or Arians, Mormons do not see Jesus as “a god” or of “like substance with the Father.” On the contrary, the LDS take is that Jesus is fully divine, a full participant in the Godhead, and (in His post-resurrected state) fully like the Father in His nature, attributes, powers, glory, etc. Yes, Mormons see Jesus as placing Himself in subjection to the Father throughout His mortal ministry. However, they sense something changed with regards to His status at the point he was resurrected. The shift in Jesus’s language about Himself after the resurrection is frequently highlighted. For example, in Matthew 5:48, Jesus (prior to His death and resurrection) said to those living on the Eastern Hemisphere: “Be ye therefore perfect, even as your Father which is in heaven is perfect.” However, after His resurrection, Jesus said to those on the Western Hemisphere: “Therefore I would that ye should be perfect even as I, or your Father who is in heaven is perfect” (emphasis added). In LDS theology, Jesus was one with the Father during His pre-moral and moral states. However, He was physically different than the Father during those periods—and He was entirely on His Father’s errand. Nevertheless, after His resurrection Jesus’s physical nature became as the Father’s, by which He assumed a status slightly different to that which He had previously had. He was now fully like the Father. (Alonzo L. Gaskill, Know your Religions, Volume 3: A Comparative Look at Mormons and Jehovah’s Witnesses, 66)