(Some “extra-curricular” material for Lesson 17 of Teachings of Presidents of the Church: Spencer W. Kimball)
Chastity is not the natural state of man. But in a religion that believes that the natural man is an enemy of God (Mosiah 3), we need not fret too much about that. There are many things we may want to do but should still discipline ourselves to avoid. Such is the life of the Christian disciple.
In his famous talk on chastity, Elder Holland said that, “Clearly God’s greatest concerns regarding mortality are how one gets into this world and how one gets out of it. These two most important issues in our very personal and carefully supervised progress are the two issues that he as our Creator and Father and Guide wishes most to reserve to himself. These are the two matters that he has repeatedly told us he wants us never to take illegally, illicitly, unfaithfully, without sanction.”
Sex can result in both the creation of life and the taking of life, and in that light, chastity makes a lot of sense. But there’s something unsatisfying about promoting this argument too strongly, especially to those who do not see a spiritual side to sexuality: with safe-sex so readily available (thus de-linking sex with “life”), is chastity unnecessary, outmoded? One could argue that even in the era of the free condom, teenage pregnancy and STDs are still rampant. On the other hand, there are plenty of careful people having sex outside of marriage. Is there a pro-chastity argument to be made that would reach the secular masses?
Perhaps not. Naturally, Elder Holland bases his defense of chastity on a religious doctrine — the doctrine of the soul (and remember, for Mormons soul = spirit and body):
[P]artly in answer to why such seriousness, we answer that one toying with the God-given–and satanically coveted–body of another, toys with the very soul of that individual, toys with the central purpose and product of life, “the very key” to life, as Elder Boyd K. Packer once called it.
Evidently, church leaders see a danger to the soul in unchastity. Some dangers are obvious: adultery can do real danger to lives (and consequently souls); some unwanted children have their souls tragically blighted from the very beginning. Elder Holland also believes that any extra-marital sex is “moral schizophrenia” one “that comes from pretending we are one, sharing the physical symbols and physical intimacy of our union, but then fleeing, retreating, severing all such other aspects — and symbols — of what was meant to be a total obligation, only to unite again furtively some other night or, worse yet, furtively unite (and you can tell how cynically I use that word) with some other partner who is no more bound to us, no more one with us than the last was or than the one that will come next week or next month or next year or anytime before the binding commitments of marriage?”
In other words, the danger of unchastity is to marriage, whether the marriage we now have, or the one we may one day enjoy. I suspect, again, that this argument will still fall flat for most non-believers. After all, what about those happy marriages where sex was a part of courtship? And what of miserable-but-chaste marriages? Or the sexual dysfunction that characterises the otherwise kosher unions of some believers?
Paul did not worry about all this. As Lauren Winner explains (writing in Christianity Today):
Sex is, in Paul’s image [1 Cor 6], a joining of your body to someone else’s. In baptism, you have become Christ’s body, and it is Christ’s body that must give you permission to join his body to another body. In the Christian grammar, we have no right to sex. The place where the church confers that privilege on you is the wedding; weddings grant us license to have sex with one person. Chastity, in other words, is a fact of gospel life. In the New Testament, sex beyond the boundaries of marriage—the boundaries of communally granted sanction of sex—is simply off limits. To have sex outside those bounds is to commit an offense against the body. Abstinence before marriage, and fidelity within marriage; any other kind of sex is embodied apostasy.
Put simply, chastity is God’s will, and as our bodies are not wholly ours, but God’s too, his will is paramount. End of story. This notion should ring true to the Christian; that it will not convince others is fairly irrelevant for our own personal application of the commandment. (I remain open to a strong secular defense of chastity, though.)
So, how to be chaste? Winner has an interesting idea. Given the characterisation of libido with “appetite,” she suggests fasting as a means of instilling discipline:
Francis of Assisi famously called his body “Brother Ass.” It is fasting, I think, that helps us say to our body, You are Brother (or Sister), but you are also Ass. Fasting, in other words, is the practice that most obviously helps us learn to discipline our physical selves. A woman of the early church known as holy Syncletia taught that “bodily poison is cured by still stronger antidotes; so fasting and prayer drive sordid temptations from us.” I have a happily married friend who puts that in a modern idiom. He says that when he wants to have sex with someone other than his wife, he fasts. In remembering that he can discipline his desire for food, my friend reminds himself that he can discipline his desire for sex, too.
Fasting as a means to chastity is an intriguing idea. Winner’s practical and candid approach to the issue is welcome (I recommend the whole article). Too often we wrap chastity up solely with guilt, not bothering to offer either a sensible apologia for it, or practical suggestions on how to be chaste. We must also try to put things into their proper perspective: the natural temptations and fumblings of youth are not sins one whisker away from murder.
Question: chastity seems to be the number one virtue promoted by the church and the centre of the “moral” life. Is the church fighting the right battle, and if so, is it fighting it in the right way? Given the crushing effects of promiscuity  I see in my own country, I think this is a virtue Christians are right to champion, but I fear we lose many young people because the quite forgivable kinks in their own sexual roads become impassable barriers to a communion with the church.
 Nor of women, but especially of men!
 I have studied some of the marriage law of the ancients and much of it seems concerned with safeguarding the legitimacy of children. In these terms, sex outside of marriage was a rather obvious danger. Acceptance of prostitution and homosexuality muddy the moral waters somewhat, however.
 For the record, I am not a fan of abstinence-only sex education. It is wholly unrealistic and doesn’t work. Oh, and as I don’t believe gay marriage to be a threat to my marriage, I think married gay sex is “more moral” (whatever that means) than unmarried gay sex. But do not rise to this threadjack!
 See Mike Ash’s article in Sunstone 143.
 And we return to the problem of automatically linking unchastity with irresponsible promiscuity.