Regarding the difficult issue of same-sex marriage, for those who are wondering about possible reasons for the Church's position, I would suggest considering some of the relevant social issues as discussed by a non-LDS advocate of traditional marriage in the article "Marriage: What It Is, Why It Matters, and the Consequences of Redefining It" by Ryan Anderson (2013). See also "The Consistency of the LDS Church's Position Regarding Legislating Marriage" by J. 2014 Update: The Church has released instructions to Church leaders regarding the same-sex marriage issue.That document may be helpful in understanding the LDS position and the approach of the Church.
The attraction itself is not a sin, but acting on it is.
Even though individuals do not choose to have such attractions, they do choose how to respond to them. Our views on the importance of gender and the divinely appointed institution of marriage between a man and a woman are also affirmed in the LDS Proclamation on the Family.
Too many of them are shocked, or feign to be, when told that what they have done in the name of petting was in reality fornication. The devil knows how to destroy our young girls and boys.
He may not be able to tempt a person to murder or to commit adultery immediately, but he knows that if he can get a boy and a girl to sit in the car late enough after the dance, or to park long enough in the dark at the end of the lane, the best boy and the best girl will finally succumb and fall.
The bride pulled her aside and said, "Do you know what I regret? " "I regret that I have kissed so many guys." "Really? I asked my husband, 'How many girls have you kissed? You just want bridesmaids and flowers and cake and a clean, worthy young man or young woman who stuck to his or her standards, as you did. How do you want to feel about your past when you're looking into the eyes of your new husband or wife?