Mormon Belief
PROPHETS
God has always chosen men on Earth to be his spokesperson, by whom He speaks to us. These men are called prophets. The Bible teaches that the Lord will do nothing save He reveal his secrets, through his servants, the prophets (Amos 3:7). Since the beginning of time, God has sent prophets among His people to teach them, guide them, and instruct them in the truths of the gospel. Adam was the first prophet, and since his day, God has continued this pattern of choosing certain men to whom He will reveal His truths. The prophets then have the responsibility to teach what they learn from the Lord to all people. This way, God's truths will be communicated to everyone on earth, and everyone will have an opportunity to learn and accept them. Prophets play an essential part in the spreading of God's truths. Without prophets, God cannot communicate some very important messages to us here on earth. That is why He has chosen to send prophets.
The main purpose of prophets is to teach all people about God's Plan and the role Jesus Christ plays in it, as Saviour of the world.
The Prophets teach those around them and then write their prophecies and teachings. These writings are called scripture. The Bible contains writings from many ancient prophets who lived in the Holy Land, the area surrounding Jerusalem. Some of these famous prophets were Moses, Abraham, and Isaiah. God promised that as long as the people were worthy, He would send prophets among them to do His work. Unfortunately, the world is not always righteous. Christ sent forth the twelve apostles before his death, in order to keep the affairs of the church running smoothly and to spread the gospel throughout all lands. He told them to go and teach all nations. The apostles went.
THE FALLING AWAY
Before Christ's death, the twelve apostles were given the authority to maintain the church and to work its ordinances and carry out the Lord's work here on earth. This authority came directly from the Lord and was given specifically to the apostles. They were the ones He had chosen for this great work. They used the powers of this authority in the right way, to organize the church, help direct the affairs, ordain priests and teachers, heal the sick, and baptize in water. After the resurrection, Christ ascended into heaven. He continued guiding His church and His apostles, even though He was not physically here on earth. He did this through what is called revelation. Revelation is communication from God to man, whether it be a great vision and dream or just the simple, more common feeling in someone's heart, God is revealing something, that is why it's called revelation. And that is how Christ continued guiding His church, even though He wasn't here. He revelaed truths to His apostles as they would study scriptures and pray about certain questions and concerns that they had.
After Christ was no longer here, the church continued its work. The Church was stable and unchanging because the Lord had provided these three bases: Apostles and prophets, revelation, and the authority to carry out His work. Without any one of these three, the church would surely fail.
Though the Christians met with much success, they also met with opposition. There were many who did not accept the teachings of Christ, spread by the apostles, and in fact, tried to destroy them. In the end, many Christians and all apostles were killed, leaving no one with the proper authority or to receive revelation. In this state, it would not be long before the changing ideas and social conditions of man would influence the once preserved truths of the gospel of Jesus Christ. Slowly, minor alterations were made to the teachings, and there were no apostles to clarify the confusion, to receive God's own input on the problems facing the Christian church. Men took control of the church and its teachings. It was no longer the church of Jesus Christ because He was no longer directing it through prophets and apostles. Those who sought control over it did not seek His will and guidance and had not been given His authority to act. The church fell into apostacy. The Bible refers to this as the falling away.
The apostle Peter prophesied of this very event by teaching that the Second Coming of Jesus Christ would not occur until the falling away had occurred. He said, speaking of the day of the second coming, "Let no man deceive you by any means: for that day shall not come, except there come a falling away first..." (2 Thes. 2:3).
THE DARK AGES
The world often makes reference to a period of darkness, called the dark ages. It was during this period that the true teachings of Christ were altered and not found in their pure form. Towards the end of the dark ages, the printing press was invented which allowed the Bible to be reproduced and carried across the world. Men once again had access to the word of God, but not to direct revelation through current prophets. The Lord's church still could not exist until God saw fit to send prophets once again, with the proper authority and revelation to guide us.
THE RESTORATION
In the spring of 1820, a young boy of 14, by the name of Joseph Smith was asking himself some questions. He was confused because of the many different Christian religions and didn't know which one to follow. His family was divided, one half joining with one religion, and the other part joining with another. Joseph had not yet made a decision because he felt unsure of it. He attended different church services and knew that different things were taught at each church. 
He knew that not all could be true because they contradicted one another's teachings. Joseph said that he didn't know what to do because he could surely not find the answers for himself being a 14 year old boy with little knowledge as to things of the world.
One day as he was reading the Bible, he came across a passage that touched his heart deeply. The scripture he read indicated a way that he would be able to leave such confusion and know of a surety where truth was. He said that "Never did any passage of scripture come with more power to the heart of man than this did at this time to mine. It seemed to enter with great force into every feeling of my heart." He read in the book of James Chapter One Verse Five..."If any of you lack wisdom, let him ask of God, that giveth to all men liberally, and upbraideth not; and it shall be given him." Joseph knew that he had to ask God directly in order to find the truth. There was so much confusion that He knew God was the only one who would be able to help him understand.
Joseph went to a grove of trees near his home, where he could be alone and ask God in prayer to help let him know which church he should join. There, as he kneeled and began to pray Joseph received an answer to his prayers. In his own words, he said..."I saw a pillar of light exactly over my head, above the brightness of the sun, 
which descended gradually until it fell upon me...When the light rested upon me I saw two Personages, whose brightness and glory defy all description, standing above me in the air. One of them spake unto me, calling me by name and said, pointing to the other--"This is My Beloved Son. Hear Him!"
God the Father and Jesus Christ appeared to Joseph Smith that morning. They taught him truths and told him not to join any church because none had all of the truth. A lot of truth had been lost through the dark ages and the falling away of the church. The churches were still guided by correct principles, but there were many holes that had to be filled. The only way to fill those holes would be to reveal the missing truths once again, through a prophet, once again, just as God had always done.
Those to whom Christ had given authority to baptize and to direct the church and the Lord's work, John the Baptist, Peter, James, and John, appeared to Joseph and gave him these same authorities. The Lord could begin again to direct the affairs of the church through those who had received this authority from Him. Christ did so and began to give revelation again to the prophet Joseph. He received and then recorded revelation that was given to him in books that are now scripture, which contain the revelations of modern prophets. Joseph Smith was called to be this first prophet after the falling away of the church. The Lord, through this prophet, reestablished the same organization of the church which He had given before, namely prophets and apostles, revelation, and authority. God spoke once again to man and continues to speak through modern prophets and the twelve apostles which live today, giving testimony of Christ and teaching His plan, as the original twelve did years ago.
The Book of Mormon
One of the many things that Joseph Smith was called to do was translate the writings of ancient prophets that lived here on the American Continent during the same time period as the Bible. Many prophets had written and taught the ancient American habitants about Jesus Christ and all that he would do on the other side of the world, in Jerusalem. These prophecies and writings begin 600 years before Christ and finish around 400 a.d. Mormon was one of these prophets and the book carries his name because he is responsible for many of its writings.
The climax of the Book of Mormon is the personal visitation of Christ to the Americas. The Bible teaches that Christ died and was resurrected on the third day. Not long after that, he ascended into the sky and then appeared here, in what we now call the Americas, among a people that had been waiting long for him. The account of Christ's appearance here in the Americas is given in the Third Book of Nephi. Nephi was a prophet at the time of Christ's appearance, he recorded what had taken place.
Click here to read the personal testimony of Joseph Smith - in his own words, what had happened.