Motivation of the Prophets and Economy of Heaven

7  O LORD, thou hast deceived me, and I was deceived: thou art stronger than I, and hast prevailed: I am in derision daily, every one mocketh me.
8  For since I spake, I cried out, I cried violence and spoil; because the word of the LORD was made a reproach unto me, and a derision, daily.
9  Then I said, I will not make mention of him, nor speak any more in his name.  But his word was in mine heart as a burning fire shut up in my bones, and I was weary with forbearing, and I could not stay.

(Old Testament | Jeremiah 20:7 - 9)

And it came to pass that the days of Ether were in the days of Coriantumr; and Coriantumr was king over all the land.
2 And Ether was a prophet of the Lord; wherefore Ether came forth in the days of Coriantumr, and began to prophesy unto the people, for he could not be restrained because of the Spirit of the Lord which was in him.
3 For he did cry from the morning, even until the going down of the sun, exhorting the people to believe in God unto repentance lest they should be destroyed, saying unto them that by faith all things are fulfilled—
4 Wherefore, whoso believeth in God might with surety hope for a better world, yea, even a place at the right hand of God, which hope cometh of faith, maketh an anchor to the souls of men, which would make them sure and steadfast, always abounding in good works, being led to glorify God.
5 And it came to pass that Ether did prophesy great and marvelous things unto the people, which they did not believe, because they saw them not.
(Book of Mormon | Ether 12:1–5)