Nehor was the first man to introduce priestcraft among the Nephites, around 91 BC. He was large in build and noted for his strength (Alma 1:2). He went among the people preaching what he called the word of God, teaching that priests and teachers ought to be popular and supported by the people rather than labor with their own hands, and that all mankind would be saved and have eternal life, so that they need not fear nor tremble before God (Alma 1:3-4).
Many believed him and gave him money. He grew proud, wore costly apparel, and established a church after the manner of his preaching (Alma 1:6). While going to preach to his followers, he met Gideon, a teacher in the church of God who had earlier helped deliver the people of Limhi out of bondage. Gideon withstood him with the words of God; Nehor, angered, drew his sword and killed Gideon, who was aged and could not fend off the blows (Alma 1:7-9).
The members of the church took Nehor and brought him before Alma, the chief judge. Alma told him this was the first time priestcraft had been introduced among the people, and that he was guilty both of priestcraft and of attempting to enforce it by the sword, having shed the blood of a righteous man (Alma 1:12-13). Nehor was condemned to die under the law given by Mosiah, the last king (Alma 1:14). He was carried to the top of the hill Manti, where he acknowledged that what he had taught was contrary to the word of God, and suffered an ignominious death (Alma 1:15).
His death did not stop the spread of priestcraft; others continued to preach false doctrines for riches and honor (Alma 1:16). His teachings persisted as a named movement within Nephite society: Amlici, who sought to be made king by popular vote and took up arms after losing, is described as being “after the order of the man that slew Gideon” (Alma 2:1), and the presiding judge at Ammonihah was “after the order and faith of Nehor” (Alma 14:16). Later groups were identified as being of the order of the Nehors, including many of the Amalekites and Amulonites among the Lamanites (Alma 21:4; Alma 24:28).