In the October 1999 General Conference, Elder M. Russel Ballard taught:
As Apostles of the Lord Jesus Christ, it is our duty to be watchmen on the tower, warning Church members to beware of false prophets and false teachers who lie in wait to ensnare and destroy faith and testimony. Today we warn you that there are false prophets and false teachers arising; and if we are not careful, even those who are among the faithful members of The Church of Jesus Christ of Latter-day Saints will fall victim to their deception...
False prophets and false teachers are also those who attempt to change the God-given and scripturally based doctrines that protect the sanctity of marriage, the divine nature of the family, and the essential doctrine of personal morality. They advocate a redefinition of morality to justify fornication, adultery, and homosexual relationships. Some openly champion the legalization of so-called same-gender marriages. To justify their rejection of God’s immutable laws that protect the family, these false prophets and false teachers even attack the inspired proclamation on the family issued to the world in 1995 by the First Presidency and the Twelve Apostles.
President Joseph F. Smith:
We can accept nothing as authoritative but that which comes directly through the appointed channel, the constituted organizations of the Priesthood, which is the channel that God has appointed through which to make known His mind and will to the world.
… And the moment that individuals look to any other source, that moment they throw themselves open to the seductive influences of Satan, and render themselves liable to become servants of the devil; they lose sight of the true order through which the blessings of the Priesthood are to be enjoyed; they step outside of the pale of the kingdom of God, and are on dangerous ground (Joseph F. Smith)
In the Book of Mormon, the prophet Samuel the Lamanite denounced the Nephite people, who had become worse than the formerly morally depraved Lamanites:
Behold ye are worse than they...
...if a man shall come among you and shall say: Do this, and there is no iniquity; do that and ye shall not suffer; yea, he will say: Walk after the pride of your own hearts; yea, walk after the pride of your eyes, and do whatsoever your heart desireth—and if a man shall come among you and say this, ye will receive him, and say that he is a prophet.
Yea, ye will lift him up, and ye will give unto him of your substance; ye will give unto him of your gold, and of your silver, and ye will clothe him with costly apparel; and because he speaketh flattering words unto you, and he saith that all is well, then ye will not find fault with him. (Helaman 13:27-28)
President James E. Faust:
In our desire to be broad-minded, to be accepted, to be liked and admired, let us not trifle with the doctrines and the covenants which have been revealed to us, nor with the pronouncements of those who have been given the keys of the kingdom of God on earth. For all of us, the words of Joshua ring with increasing relevance. “Choose you this day whom ye will serve; … but as for me and my house, we will serve the Lord” (Josh. 24:15). (James E. Faust, "Keeping Covenants and Honoring the Priesthood")
Elder Dallin H. Oaks:
In our system of Church government, evil speaking and criticism of leaders by members is always negative. Whether the criticism is true or not, as Elder George F. Richards explained, it tends to impair the leaders’ influence and usefulness, thus working against the Lord and his cause. (In Conference Report, Apr. 1947)
“What are we, that ye murmur against us?” Moses asked them. “The Lord heareth your murmurings which ye murmur against him: and what are we? your murmurings are not against us, but against the Lord.” (Ex. 16:7–8.)