"And I spake unto Sam, making known unto him the things which the Lord had manifested unto me by his Holy Spirit. And it came to pass that he believed in my words."
Nephi goes to Sam and speaks to him about the things he had learned and by sharing his testimony Sam accepted the things Nephi had learned. Sam was more receptive to the things of the Lord than Laman and Lemuel, by being so, he was better able to understand the mysteries of the Lord.
#Nephi approach Sam, speak about things himself learn from God. Sam accept brother testimony. Sam willing accept thing from God. #Laman, #Lemuel accept things not. Sam understand God can.