In Stephen E. Robinson’s book “Are Mormons Christians?” the author gives a standard dictionary definition of the word “Christian”:
According to Webster’s Third New International Dictionary the term Christian may be defined in a number of ways, but the most common is “one who believes or professes or is assumed to believe in Jesus Christ and the truth as taught by him: an adherent of Christianity: one who has accepted the Christian religious and moral principles of life: one who has faith in and has pledged allegiance to God thought of as revealed in Christ: one whose life is conformed to the doctrines of Christ.” The second most common meaning is “a member of a church or group professing Christian doctrine or belief,” 1
By any of these definitions, Latter-day Saints would identify themselves as Christians.
The only way to argue against Latter-say Saints being Christians, is to define Christianity in such a way as to exclude Latter-day Saints. For example one could argue that “Latter-say Saints do not believe the truth as taught by Jesus” or “Latter-day Saints lives do not conform to the doctrines of Christ”. However who is the authority to determine what is “the truth as taught by him” or what is “the doctrine of Christ”?
As Daniel O. McClellan has put it:
…given that Christianity must be allowed to define itself…in any objective approach to the question, Mormonism must be allowed to participate in that process of definition. To preclude Mormonism from Christianity’s self-definition is…begging the question. It assumes the conclusion in setting up the premise. Would it be begging the question in the opposite direction to allow Mormonism to contribute to the definition of Christianity? No. Mormonism claims to be Christian just like (others claim) to be Christian, and according to many Christians, Mormonism meets the criteria. 2
Latter-day Saints could equally argue that other Christian denominations “do not believe the truth as taught by Jesus” or that their “lives do not conform to the doctrines of Christ”. The bottom line is that any attempt to exclude “Mormonism” from Christianity, on the basis of key “differences” is simply begging the question.
Latter-day Saints identify themselves as Christians and claim to teach the restored gospel of Jesus Christ as revealed in the Bible and other scripture. Gordon B. Hinckley said:
“We are Christians in a very real sense and that is coming to be more and more widely recognized. Once upon a time people everywhere said we are not Christians. They have come to recognize that we are, and that we have a very vital and dynamic religion based on the teachings of Jesus Christ.
We, of course, accept Jesus Christ as our Leader, our King, our Saviour…the dominant figure in the history of the world, the only perfect Man who ever walked the earth, the living Son of the living God. He is our Saviour and our Redeemer through whose atoning sacrifice has come the opportunity of eternal life. Members of The Church of Jesus Christ of Latter-day Saints pray and worship in the name of Jesus Christ. He is the center of our faith and the head of our Church. The Book of Mormon is Another Testament of Jesus Christ and witnesses of His divinity, His life, and His Atonement.”
- Robinson, Are Mormons Christians?