Alma 21
When Aaron and his brethren arrived among the Lamanites they came to a land that was peopled with Nephite dissenters (Amalekites and Amulonites) – no wonder they were more hardened. When the Amalekite challenged Aaron asking how Aaron could know they needed to repent Aaron simply asked if they believed in Christ. The Amalekite defiantly replied that he did not believe that Aaron and the Nephites could not know of any such foolishness. Note that Lamoni did not require that anyone believe in the words of Ammon – which he could have done as king – that shows that he really understood the nature of the Lord he worshiped.