Nephi continued by giving his listeners a sermon based on Old Testament demonstrations of God’s power through his servant Moses. He then said: “If God gave unto this man such power, then why should ye dispute among yourselves, and say that he hath given unto me no power whereby I may know concerning the judgments that shall come upon you except ye repent?” (v. 12).
Nephi directed his listeners’ attention to the incident where Moses made a serpent out of brass, placed it on a pole, and urged as many as had faith to look thereon and be healed from the bites of poisonous snakes.
“According to the Bible, when the people of Israel were being bitten by serpents and some of the people were dying, the Lord commanded Moses to make a serpent ‘and set it upon a pole: and it shall come to pass, that every one that is bitten, when he looketh upon it, shall live. And Moses made a serpent of brass, and put it upon a pole, and it came to pass, that if a serpent had bitten any man, when he beheld the serpent of brass, he lived.’ (Numbers 21:8–9.)
“That is the end of the account in the Bible. However, the account in the Book of Mormon indicates that when Moses lifted up the brazen serpent he did ‘bear record that the Son of God should come. And as he lifted up the brazen serpent in the wilderness, even so shall he be lifted up who should come. And as many as should look upon that serpent should live, even so as many as should look upon the Son of God with faith, having a contrite spirit, might live, even unto that life which is eternal.’ (Helaman 8:14–15).
“The Savior also indicated that the ‘brazen serpent lifted up by Moses’ was a type (shadow, or example) of his own crucifixion when he said: ‘And as Moses lifted up the serpent in the wilderness, even so must the Son of man be lifted up: That whosoever believeth in him should not perish, but have eternal life.’ (John 3:14–15.)”
(Daniel H. Ludlow, A Companion to Your Study of the Book of Mormon, pp. 243–44).