who is nephi

Mormon is one of the final authors who compiled writings from his ancestors who lived nearly one thousand years before he did; hence, the name of the volume. Nephi, however, is the author of the first couple of books within The Book of Mormon. Nephi lived 600 years before Jesus Christ was born, and Mormon lived about 300 years after that. Nephi is the 4th son of a prophet named Lehi, who was born a Jew and lived in Jerusalem. After Lehi receives a vision from God that Jerusalem would be destroyed, he leads his family out of danger and into the wilderness. The family consists of Lehi, his wife Sariah, and his sons Laman, Lemuel, Samuel, and Nephi. Nephi and Samuel are the most obedient and loyal to their father while Laman and Lemuel cause many problems while in the wilderness.
Eventually, Nephi receives a commandment to build a boat and cross the ocean to the "promised land," which ends up being the Central/Southern American continent. Nephi's family invites another family to go with them and they make it to their destination after many years of traveling over land and by sea. Once Lehi dies, however, Laman and Lemuel fight for dominance over the growing family in the new land. They want to be kings and eventually become so jealous of Nephi's strength and goodwill that they seek to kill him. Nephi is therefore told by God to take his family, and anyone else who is loyal to him, and get away from his brothers. The result is a family rivalry that spans a thousand years of peace and war throughout many generations of Lehi's posterity. The two groups that make up a civilization during that time period distinguish themselves as either Nephites or Lamanites.
One of the most popular quotes from Nephi's writings is the following:

I will go and do the things which the Lord hath commanded, for I know that the Lord giveth no commandments unto the children of men, save he shall prepare a way for them that they may accomplish the thing which he commandeth them (1 Nephi 3:7).