3Ne Ch5

The Nephites repent and forsake their sins while Mormon starts to compile the histories and records of the Nephites. He is a disciple of Christ and preaches the everlasting word to the people and the truths that he reads about in the records.
At this time there weren't any unbelievers in the midst of the Nephites and they knew Christ had come from the signs that prophets had given, making the people diligent in repenting and serving God day and night (v1-3). The robbers they had taken prisoner after surrounding them were taught the truths of the gospel and set free if they repented and covenanted with God while the others who rejected and would not forsake their murderous ways were condemned and punished (v4-5). This is how they stopped the secret combinations and wickedness for 4 years until the end of the 25th year since Christ's birth (v6-7).
There were many great and marvelous things done but they are too much to put into one book so there are other records containing all the goings on but the shorter but still true account is this that was started by Nephi which is where I, Mormon, have based this book on (v8-12). Mormon was named after the land of Mormon where Alma had established the first church of the people, he was called to be a disciple of Christ and declare his words to the people but as of right now, the time has come to write records of the things which have been done (v13-14). There is only a small portion that is written in the Book of Mormon about the whole time since Lehi left Jerusalem, but it comes from many other records from other prophets then a record of Mormon's life (v15-17).
Everything that is written in Mormon's book has been true and just even if there are some things that can't fit into them including the rest from here on out that is Mormon's life and events while he is alive (v18-19). He is a descendant of Lehi and is grateful for his ancestor's who have given knowledge and blessings from their righteousness (v20-22). The Lord will gather all who have scattered who are a part of the house of Jacob because they have been promised to be restored because of the promise the Lord has covenanted with them (V23-26).