Children cannot discern false teachings.
The duty of the mother is to watch over her children, and give them their early education, for impressions received in infancy are lasting. You know, yourselves, by experience, that the impressions you have received in the dawn of your mortal existence, bear, to this day, with the greatest weight upon your mind. It is the experience of people generally, that what they imbibe from their mothers in infancy, is the most lasting upon the mind through life. This is natural, it is reasonable, it is right. I do not suppose you can find one person among five hundred, who does not think his mother to be the best woman that ever lived. This is right, it is planted in the human heart. The child reposes implicit confidence in the mother, you behold in him a natural attachment no matter what her appearance may be, that makes him think his mother is the best and handsomest mother in the world. I speak for myself. Children have all confidence in their mothers; and if mothers would take proper pains, they can instil into the hearts of their children what they please. You will, no doubt, recollect reading, in the Book of Mormon, of two thousand young men, who were brought up to believe that if they put their whole trust in God and served Him, no power would overcome them. You also recollect reading of them going out to fight, and so bold were they, and so mighty their faith, that it was impossible for their enemies to slay them. This power and faith they obtained through the teachings of their mothers. 1
Daniel Sylvester Tuttle
In Utah, especially, schools were the backbone of our missionary work. Adults were fanatics, and so beyond the reach of our influence; or else were apostates, and so, grossly deceived once, were unwilling to listen again to any claims of the supernatural. But the plastic minds and wills of the young we could hope to win to better views and mould in nobler ways. 
W. M. Welch
The innocence with which children come into the world is one of the awesome responsibilities of all who, in any way, influence their lives. And to see such unstained innocence neglected or abused, or exposed to evil or unwholesome influence, or warped by bad example, or by false teaching — or by failure to teach — is a sobering concern.
There are many who have responsibility for teaching children: parents, teachers, friends, anyone who in any way enters their lives, including the makers and promoters of products, of policies; creators of entertainment, and the whole community, publicly and privately. And children in their innocence have a right to be protected from exploitation and from evil influence.
As to teachers, the following is cited from a significant source: “The personal influence of the teacher, in molding the character of the pupils, is the most important element in their education…. In morals, a teacher cannot teach what he is not. If he talks what he is not, it were better not said, for his life talks more forcibly and is sooner believed, both by children and adults.” 
Always we must remember that the teacher teaches himself. As Henry Adams said it: “A teacher affects eternity; he can never tell where his influence stops.” 
Richard L. Evans
People who speak of their private lives as a thing apart from their professions would well remember this sentence from Stanford University’s Dr. David Starr Jordan: “There is no real excellence in all this world,” he said, “which can be separated from right living.”  
- ↑ comment by Protestant missionary Bishop Daniel Sylvester Tuttle, Reminiscences of a Missionary Bishop. New York: Thomas Thitaker, 1906. p. 373, as quoted in Jack Monnett, Revealed Educational Principles, p. 57
- ↑ W. M. Welch, How to Organize, Classify and Teach a Country School
- ↑ The Education of Henry Adams, ch. 20
- ↑ The University and the Common Man
- ↑ Richard L. Evans, Conference Report, April 1969, p.73-74