“The fundamental principles of our religion are the testimony of the Apostles and Prophets, concerning Jesus Christ, that He died, was buried, and rose again the third day, and ascended into heaven; and all other things which pertain to our religion are only appendages to it.” (“Chapter 3: Jesus Christ, the Divine Redeemer of the World,” Teachings of Presidents of the Church: Joseph Smith, (2007),45–56)
On the surface, this is just a straightforward assertion of the place Jesus Christ has in Mormonism. Not only is Christ the center of all we do, but He is also the source of all other things. In short, if you are curious why Mormons do something, the answer is “Because of the Atonement.”
Then there is the not-so-obvious principle. This is Joseph Smith himself. Specifically, Joseph Smith’s relationship to Jesus Christ.
However, Mormons see Jesus Christ as God’s only begotten Son, as our Savior. Joseph Smith’s mission, then, was to clarify who Christ was, and to reemphasize His role as our Savior. In this sense, Jesus Christ and Joseph Smith are both necessary to understand who Latter-day Saints are.
In fact, the First Presidency of the Mormon Church (the supreme governing council for the worldwide Mormon Church) wrote in 1936:
“Two great truths must be accepted by mankind if they shall save themselves: first, that Jesus is the Christ, the Messiah, the Only Begotten, the very Son of God, whose atoning blood and resurrection save us from the physical and spiritual death brought to us by the Fall; and next, that God has again restored to the earth, in these last days, through the Prophet Joseph, His holy Priesthood with the fullness of the everlasting Gospel, for the salvation of all men on the earth.” (Messages of the First Presidency 6:4-5.)
People may agree or disagree with this assessment. But at least we should be clear what the position of the Church of Jesus Christ is in relation to both Christ and to Joseph Smith.
For me, understanding this point—that Joseph Smith is a prophet or a witness of Christ—is the groundwork of all other things. Once I have this foundational understanding in place, then everything else makes sense. I get a sense of order and purpose in my life. I can finally see where I am going, and I can know who I am. And that makes all the difference in the world.