"Mormons have another Jesus!" "Mormons' Jesus is not the Jesus of historical Christianity!" "Mormons are not Christian."
These are very typical slurs hurled at Mormons by anti-Mormons. They are slurs because they are not academic observations used to stimulate understanding. They are intended as insults to the closely held personal beliefs of millions of Mormons. I can actually agree with the first two statements, as they are true. But the history of Christianity is conclusive in showing Mormons are Christians.
I heard one goof-ball say "What if I say I am a Mormon, I just don't believe in Joseph Smith, the Book of Mormon, the First Vision or the restoration of priesthood authority? That's the same as saying you are Christians."
It is if you are an idiot.
First, anti-Mormons don't get to define what a Christian is to anyone other than themselves. I seriously don't care if someone doesn't think I am a Christian. Second, I believe in the same foundational document, the Bible, as they do, but I interpret it according to my conscience, not theirs. Lastly, their definition of a Christian would exclude all of the people in the Bible, including Jesus. Academics, Jews and Mormons are unable to locate the doctrine of the Trinity in the Bible. It is a conclusion based on a philosophical perspective which is not Biblical. The Catholic Encyclopedia states it is nowhere in the Old Testament, and only inferred in the New Testament.
Drilling down, the LDS Articles of Faith grant the right to believe and worship to each person individually. So we expect to be excluded from other people's beliefs. And we define what it means to be LDS. But the Bible provides no definition of what a Christian is beyond one who believes in Jesus. There is no doctrinal litmus test. Bart Ehrman has written and taught extensively on the "Lost Christianities" which were divergent beliefs from what is now considered "orthodox" Christianity. They believed in some way in Jesus. The current "orthodox" Christianity is, from a historical standpoint, the result of fortunate circumstances and some lucky breaks in history. The Arian controversy, for example, could easily have resulted in a very different theology about Jesus, with Athanasian theology considered apostate.
We believe in Jesus, as described fully in the Bible. In fact I would assert we, as Mormons, believe more closely in the Biblical Jesus than any other people, as we understand the circumstances of Christ in the eternities and the context of the Bible. No later than February 1832 the clear description of man's destiny to become like God is revealed, and soon thereafter the Book of Abraham asserts this understanding of a Council of Gods was the background of the Bible. Sure enough, we get archaeological discoveries about 100 years later that show the people of the Bible DID know this was the background of the Bible. See Mark Smith's, "The Origins of Biblical Monotheism" or visit Micheal Heiser's website, and see how a devout Evangelical scholar presents the indisputable fact of history that Israel DID believe that God was among many gods.
Even more pointedly, early Christians believed and understood the teachings of the Bible to mean men could become gods. The earliest existing defense of the Christian faith was written by Justin Martyr around 140 AD. He notes Jesus is a "second god" after the creator of all things. He also notes our faith is that we will also become gods. What it meant to become a "god" gradually evolves, until we see Athanasius try to harmonize this belief with Trinitarianism by saying it is about fellowship with God and Jesus, not our own development.
But it is realistic to argue that Mormons are Christians, because we do believe what the Bible teaches about Jesus, not the stuff added over the centuries after the authors of the Bible had died.
Second, the Bible is the common document between anti-Mormon Christians and Mormon Christians. It is not the Book of Mormon, the First Vision or any other particular LDS belief. But let's consider the Catholics vs. Evangelicals. Are they both Christian? Today we would say yes, but historically the Catholic Church did not consider Evangelicals to be Christians for hundreds of years. They literally discriminated and killed each other. Protestants then really tried to get the Bible in the hands of commoners. This was a great thing, unless you were killed for trying to do so. This has many positive things, especially about personal spirituality.
But there are some negative things. Specifically in not understanding the context or content of the Bible. Or reading the Bible with a pre-existing prejudice from extra-Biblical teachers. Today we hear most Evangelicals argue it is by faith alone through grace alone that people are saved. But that simply ignores the plain teaching of the Bible that we do contribute to our salvation. God wants to save us, according to the Bible, but we have to follow him. Calvinists go further and say God has already decided who to save, which is the logical conclusion of Evangelical doctrine, and we are unable to do anything to become saved if we are not on God's pre-existing list.
I am routinely accused of hating the Bible because I discuss issues of textual criticism with people. I love the New Testament. I love truth even more. To fail to try to understand not just what the words mean, but what the original words were, is, in my opinion, not following Jesus' admonition that we demonstrate our love by keeping his word.
Finally, as I mentioned above, the Catholics defined the Protestants as non-Christians. It did not mean anything. Walter Martin did a great job of creating hatred of the "cults". Read early Christian history. They considered themselves a cult. They were initially Jews (followers of Abraham and Moses) who kept that faith and added to it Jesus and his teachings. They were called "Christians" because their Hebrew beliefs center on the interpretation added to it by Jesus, and the belief that Jesus was the son of God. Read John 10. This was blasphemy to the "orthodox" religion of the day, and they felt justified in stoning Jesus. Or beating the Apostles. Or killing Christians. Or, calling them names like "heretics". They eventually kicked them out of the synagogues, because they were different. The Christians considered themselves the children of Abraham, either by birth or adoption. They had the Old Testament, which they considered scripture, and they added to it new revelation. They were proud to be called Christians. Men like Paul still considered themselves Jews, regardless of the name calling, as well as Christians.
And so do we.
Mormons are Christians.