Here are some additional thoughts regarding the unusual changes in the Lamanites that are described in 3 Nephi 3:14-16.

Wickedness and abominations increase among the people—The Nephites and Lamanites unite to defend themselves against the Gadianton robbers—Converted Lamanites become white and are called Nephites. About A.D. 5–16.

Nephi, the son of Helaman, departs out of the land, and his son Nephi keeps the records—Though signs and wonders abound, the wicked plan to slay the righteous—The night of Christ’s birth arrives—The sign is given, and a new star arises—Lyings and deceivings increase, and the Gadianton robbers slaughter many. About A.D. 1–4.

The Nephites who believe Samuel are baptized by Nephi—Samuel cannot be slain with the arrows and stones of the unrepentant Nephites—Some harden their hearts, and others see angels—The unbelievers say it is not reasonable to believe in Christ and His coming in Jerusalem. About 6– 1 B.C.

The Lord chastened the Nephites because He loved them—Converted Lamanites are firm and steadfast in the faith—The Lord will be merciful unto the Lamanites in the latter days. About 6 B.C.

Samuel predicts light during the night and a new star at Christ’s birth—Christ redeems men from temporal and spiritual death—The signs of His death include three days of darkness, the rending of the rocks, and great upheavals of nature. About 6 B.C.

Samuel the Lamanite prophesies the destruction of the Nephites unless they repent—They and their riches are cursed—They reject and stone the prophets, are encircled about by demons, and seek for happiness in doing iniquity. About 6 B.C.

Men are unstable and foolish and quick to do evil—The Lord chastens His people—The nothingness of men is compared with the power of God—In the day of judgment, men will gain everlasting life or everlasting damnation. About 6 B.C.

Nephi persuades the Lord to replace their war with a famine—Many people perish—They repent, and Nephi importunes the Lord for rain—Nephi and Lehi receive many revelations—The Gadianton robbers entrench themselves in the land. About 20–6 B.C.

The Lord gives Nephi the sealing power—He is empowered to bind and loose on earth and in heaven—He commands the people to repent or perish—The Spirit carries him from multitude to multitude. About 21–20 B.C.