Mosiah 4:30

30 But this much I can tell you, that if ye do not watch yourselves, and your thoughts, and your words, and your deeds, and observe the commandments of God, and continue in the faith of what ye have heard concerning the coming of our Lord, even unto the end of your lives, ye must perish. And now, O man, remember, and perish not.

2 Nephi 3:21

21. Because of their faith their words shall proceed forth out of my mouth unto their brethren who are the fruit of thy loins; and the weakness of their words will I make strong in their faith, unto the remembering of my covenant which I made unto thy fathers.