Mosiah 4:30

Mosiah 4:30 "But this much I can tell you, that if ye do not watch yourselves, and your thoughts, and your words, and your deeds, and observe the commandments of God, and continue in the faith of what ye have heard concerning the coming of our Lord, even unto the end of your lives, ye must perish. And now, O man, remember, and perish not."

Alma baptized Helam at the waters of Mormon

The following is an extract from: 

www.ldsces.org/inst_manuals/bm-ssg/bm-ssg-05-mos.htm

• Who Wrote the Book of Mosiah?

The books in the Book of Mormon​ that came from the small plates of Nephi (1 Nephi–Omni) were not abridged by Mormon. He placed those plates, without any changes, with his abridgment of the large plates. Beginning with the book of Mosiah, we are reading Mormon’s abridgment of the large plates of Nephi. The book of Mosiah is named for the king and prophet Mosiah who was the son of King Benjamin and the grandson of King Mosiah I, whom you read about in the book of Omni.

• What Can You Find in This Book?

In Mosiah you will read about great heroes, such as King Benjamin, King Mosiah II, Abinadi, and Alma the Elder​. You will also find accounts of great villains, such as King Noah and Amulon. Most importantly, you will find the gospel of Jesus Christ explained in great sermons and illustrated in fascinating stories. The book of Mosiah begins about 130 B.C. and ends about 91 B.C. It is not, however, one continuous story. In his abridgment, Mormon wove together the accounts of three related groups of Nephites:

• The Nephites in Zarahemla (Mosiah 1–8; 25–29)
• The Nephites who followed Zeniff back to the land of Nephi (Mosiah 9–22)
• Alma the Elder and his group of converts (Mosiah 23–24)