Every sin is associated with a punishment. Part of the punishment for the sin of lust is to lose the Spirit of God, he that looketh on a woman to lust after her, or if any shall commit adultery in their hearts, they shall not have the Spirit, but they shall deny the faith and shall fear (DC 63:16).
Ezra Taft Benson
"‘The lusts of your eyes’ - in our day what does that expression mean? Movies, television programs, and video recordings that are both suggestive and lewd. Magazines and books that are obscene and pornographic… .
“We counsel you, young men, do not pollute your minds with such degrading matter, for the mind through which this filth passes is never the same afterwards.” (Conference Report, April 1986, p. 45)
Spencer W. Kimball
“Each person must keep himself clean and free from lusts…He must shun ugly, polluted thoughts and acts as he would an enemy. Pornographic and erotic stories and pictures are worse than polluted food. Shun them. The body has power to rid itself of sickening food. The person who entertains filthy stories or pornographic pictures and literature records them in his marvelous human computer, the brain, which can’t forget such filth. Once recorded, it will always remain there, subject to recall.” (Ensign, July 1978, pp. 3-7 as taken from Latter-day Commentary on the Book of Mormon compiled by K. Douglas Bassett, p. 335)
Gordon B. Hinckley
“The girl you marry can expect you to come to the marriage altar absolutely clean. She can expect you to be a young man of virtue in thought and word and deed. I plead with you boys tonight to keep yourselves free from the stains of the world…You must not fool around with the Internet to find pornographic material…You must not rent videos with pornography of any kind…Stay away from pornography as you would avoid a serious disease. It is as destructive. It can become habitual, and those who indulge in it get so they cannot leave it alone. It is addictive…it seduces and destroys its victims…I plead with you young men not to get involved in its use. You simply cannot afford to. The girl you marry is worthy of a husband whose life has not been tainted by this ugly and corrosive material.” (Ensign, May 1998, p. 49 as taken from Latter-day Commentary on the Book of Mormon compiled by K. Douglas Bassett, p. 337)