Alma, the elder:
The last few weeks we have been studying a prophet from the Book of Mormon named Alma. And let me just clarify here that we, as Mormons, believe in and study the Bible - Old and New Testament, and The Book of Mormon. We also believe, as Joseph Smith told a reporter back in his day "all that God has revealed, all that he does now reveal, and we believe that he will yet reveal many great and important things pertaining to the kingdom of god." In other words, we believe in modern day revelation as well, which is why some of our prophets of the week have been "latter day", or from modern times.
I guess if there was one absolute, most important thing that I would want people to know about me, as a Mormon, is that I believe in the Savior, Jesus Christ, with all my heart. I believe that he is the one and only begotten son of God, that he died for us on the cross, was resurrected as well, and is in Heaven again watching over us all. All of the prophets from all of our scriptures testify of Him. We do not worship our prophets - we worship God the Father and His Son, Jesus Christ. We appreciate our prophets, and when we read about them and the things they taught we come even closer to our one and only Savior, Jesus Christ, and our Heavenly Father.
So, back to Alma. There was once a very wicked king named Noah. (Not Noah from the Bible; that is a different story.) He took advantage of his people, lived off of them, and lead his people to do all kinds of atrocities. He made it difficult for anyone to know anything about God and Jesus Christ. A very brave man named Abinidi was called by God to be a prophet and go to King Noah and tell him whats what. He, of course, testified to the King of Jesus Christ and told him that it was not too late to repent; that he should change his ways and lead his people in righteousness. Well, King Noah did not listen to Abinidi. In fact he was very angry with him and sentenced him to death if he would not take back his testimony.

Abinidi did not take back his testimony and died for it. Little did he know (or maybe as he died he felt comfort because he did know) - that someone was listening to all he had to say. King Noah had many wicked high priests in his service; one of them was Alma. Alma believed Abinidi. Alma repented/changed his life. He fled from King Noah's service and taught other people about Jesus Christ; taught them the words of Abinidi. He established Christ's church, taught the people to endure trials without losing their testimonies, and remained a prophet himself for the rest of his days.