The Mormons are a Christian sect created by their founder, Joseph
1. Hell is not a defined place
Although the LDS faith is indeed Christian, they do not think that the eternal punishment described in the Bible is a place called Hell. Rather, Mormons' beliefs are of the three degrees of glory. Essentially, members of the LDS faith belief that we start life with God and come to Earth to get a body and be tested to
grow spiritually. Upon death, worthy members go to Spirit Paradise where they essentially act as missionaries for everyone else, who is in Spirit Prison. Then, on judgment day, we are assigned one of three degrees of Glory: the Telestial Kingdom, the Terrestrial Kingdom, and the Celestial Kingdom (heaven).
The subject of Hell has been broached a few times, and from my understanding, it's still a very fuzzy concept in the LDS faith. However, I think that this quote from Understandable Religion sums it up:
"Now, it may be contended that a judgment, with some degree of salvation for all, encourages the sinner to pursue his dark ways. Not so. However generous the judgment, it is measured by our works. Our punishment will be the heavy regret that we might have received a greater reward, a higher kingdom, had our lives conformed more nearly to truth. Such remorse may yield keener pain than physical torture."
Essentially, the Mormons' beliefs are probably that Hell is the eternal feeling of regret you have for not making it to the Celestial Kingdom. Others have postulated that it means Outer Darkness (a place where people who have a full knowledge and certainty of God and disobey him go), or even a temporary place of punishment during Judgment Day. Regardless, one thing is for sure: the Mormons' beliefs do not accommodate for a place of eternal fire and brimstone for our sins.
2. You can become a God or Goddess
Another quite exhilarating part of the Mormons' beliefs is that worthy members will eventually become Gods or Goddesses; thus, that Mormonism is a cycle of God makers, if you will. This belief of the Mormons is affirmed in this quote in The Gospel Through the Ages:
"Thus all men who ascend to the glorious status of Godhood can do so only by one method - by obedience to all the principles and ordinances of the Gospel of Jesus Christ. If to obtain eternal life means to enjoy the same type of life that God lives and to experience similar experiences, then those people who receive it to the fullest degree shall actually be Gods." (The Gospel Through The Ages, pp. 114-117)
The belief that followers can become Gods and Goddesses requires them to abide by the Church's standards and get married in the temple, and thus be exaltated to the highest degree of the Celestial Kingdom, where the couple will grow and eventually become Godly. (No one can be a God of a universe solo.) It is with this belief that the conclusion can be drawn that God was not always God. The LDS faith states that God himself went through the process of being a God already. This bit of doctrine is considerably different from that of other Christian faiths, but certainly puts into perspective the "eternal plan of happiness" put forth by the Mormons.
There is one thing I believe all Christian faiths can agree upon: the story of Adam and Eve. In case you are not aware, God created Adam and Eve, and left them in a state of perfection known as the Garden of Eden. They were instructed that they could not eat the fruit from the Tree of Knowledge of Good and Evil, for doing so w
ould banish them from the Garden forever. However, a serpent tempts Eve, and she goes for it, as does Adam. From this decision, evil entered the world, and human life as we know it began.
While most Christian sects believe the Garden was located somewhere in the Middle East or southern Asia (Iran, Sumeria, Sri Lanka), the Mormons believe that the Garden was once located in a place called Adam-ondi-Ahman, near Independence, Missouri. To this you may be thinking, "How on Earth did we end up with Abraham around Babylon?" The Mormons' beliefs justify this by citing the split of Pangaea.
Although Adam-ondi-Ahman is in the Adamic language, some have speculated it to mean "Valley of God." Regardless of what it means, it is clear that the LDS faith certainly differs from popular Christianity on the location of what they claim to be our origins: the Garden of Eden.
Hopefully you now have a good understanding of the 3 ways that Mormons' beliefs set them apart from other Christian sects. Through the complex network of worlds instead of Heaven and Hell, the cycle of God makers, and Adam-ondi-Ahman's significance in the interpretation of the Bible by the LDS faith, the Mormons certainly add their own unique flavor to the world of Christianity.