When I say unmarrieds shouldn't live together, I'm not talking about living in a convent, or with a roomie, sibling-style. I'm talking about moving in with a lover. And unmarrieds definitely shouldn't do it.

Most pre-, para-, or pseudo-marital living together takes place in the first decade of young adulthood, and it's clear why. Young people don't want to stay with their parents. They're not ready for marriage - not yet - because they don't really know themselves, and they've got a lot more changing to do. And they're lonely. Very lonely.

Then that young man or young woman finds someone to like, someone of the opposite sex to communicate with, to laugh with, and so forth: hurrah! The couple moves in together.

What's wrong with that?

For one thing, people who sleep together often end up pregnant. Twenty years ago people thought contraceptives would eliminate for good the little possibility of pregnancy. Today, 1 million IUDs, 100 billion birth control pills, and 18 million miserable abortions later, it obviously isn't so. Women's magazines everywhere now run feature-length exposes on just how often drugs, devices, jellies, and the like fail to prevent pregnancy. As Mother Jones magazine glumly conceded in a recent editorial: "Much as we wish it otherwise, sex is a reproductive act. "

Reproductive acts should be engaged in only by people willing to reproduce. Parenthood - even if only a possibility - takes more of a commitment than a decision to merge four rooms of furniture and co-sign a one year lease. It takes a lifetime guarantee.

Sex, of course, is also unitive - just what live-in lovers want. It's a vital bond with a special human being. If unwanted pregnancies could be firmly excluded, wouldn't the blessings of intimacy make cohabitation a positive good - or at least harmless? Probably not. Young people who've been there can give the reasons why not.

"My own parents divorced 15 years ago," says Marsha, a 22-year-old graduate student, "so I was determined not to jump into marriage. That's why I moved in with Tom - so we could develop our relationship and get to know each other first.

"It went from beautiful to miserable in about four months," she confesses. "I was knocking myself out to please him, feeling insecure whenever the arrangement seemed the least bit shaky. And I was using sex in a way that was false to myself. Intercourse was my way of reiterating, 'The relationship is still on'; of asking 'Is the relationship still on?' It was my way of saying, 'Keep me, I'm good!' (even when sex wasn't always that good), and of reassuring myself, 'See, he still loves me.'

"Important questions were never settled, things like: 'What if I get offered a good job in another state?' or 'What if he decides to go back to school?' or 'The Pill is making me depressed - should I stop taking it?' We'd just end up in bed again, without resolving things. I got to the point where I felt like yelling, 'Sex, schmex! I just want you to talk to me!' "

A recent study conducted by Steven Naifeh and Gregory White Smith, Why Can't Men Open Up? Overcoming Men'5 Fear of Intimacy, suggests that for me, too, sex is the primary source of inner conflict, especially when they're trying to get to know a woman.

"As both a proving ground for his masculinity and as an invitation to intimacy, sex becomes a focus of his fears of dependence," report Naifeh and Smith. They claim that eros triggers all kinds of defense mechanisms in men - especially the emotional-detachment reaction which so often hurts and angers women and often baffles the men as well. What's Naifeh and Smith's advice? If what you want is to build a relationship, avoid the anxieties and ambivalence of uncommitted sex.

What happened to Marsha?

"I told Tom I wanted to move out and think things over. I wanted him to really see me and hear me as a person - something our sexual involvement made it hard for him to do. I wanted perspective - and friendship.

"I must say that - after the initial shock -'- Tom rose to the challenge. We spent a whole year getting to know each other every way but horizontally. We must have logged 1,000 hours just talking. And I knew I wasn't sliding into something through compliance and neediness and emotional fuzziness: I was exercising real sexual intelligence. That gave me new respect for myself - and for Tom."

And now? "We're getting married. It took a while, but now we know we're committed."

What about unmarrieds who really are "committed"? These live-in couples characterize their relationships not as premarital, but as non-ceremonial. "We're already

married in our own eyes," they say. "What do social, legal, or religious sanctions have to do with our private life together?"

Sexual partnership creates a web of social relationships that extends well beyond individual men and women. To the extent that "private relationships fail to celebrate this - and marriage is the universal way of celebrating it all such couples are deprived of the connectedness that gives life resonance and texture.

Couples need a wedding to serve notice on relatives, neighbors, workmates, and friends: "That is it! This person is my partner for life. If you respect me, respect this marriage." And because all loving couples, even the most devoted, are still subject to stress, random sexual hungers, and hard times, the more social support they can assemble around their union, the better.

Marriage, unlike living together, also involves legal obligations designed to protect the rights of vulnerable parties. The theory and the actual practice may be imperfect or worse (for example, there may be little enforcement of child-support laws, and no protection at all from marital rape). But a preference for "living together" over legal marriage may express a denial that spouses owe to

each other and to their children certain publicly recognized obligations. Refusal to acknowledge this makes you not just a private cad, but potentially an agent of serious social injustice.

For Christians and Jews, there is yet another dimension. Scripture teaches that marriage and the family have God as their author. It is the teaching of biblical faith that sex belongs to marriage and to marriage alone.

Cohabitation is not marriage, and it does not prepare couples for marriage. I believe that even with the best intentions, cohabitation lacks integrity. "If you sit, sit. If you stand, stand. Don't wobble," said Buddha. My translation: If you're single, be single. If you're married, be married. Don't mess around.

Some more reflections to consider

Because we have some extra space I'd like to add some extra thoughts on the topic of living together and premarital sex.

The church is opposed to couples living together and engaging in premarital sex because they are acting as if they are married when, in fact, they are not. To live together as if you were married when, in fact, you are not is a lie and therefore morally wrong.

Many couples sincerely believe that living together is a good way to prepare for marriage. On the surface that seems to make a lot of sense. You can really get to know your partner, his/her habits and behaviors in the early morning and at night, etc. But, statistics show that there is a higher rate of divorce among couples who live together prior to marriage than among couples who choose to go the traditional route.

Research shows that couples usually move in together without much discussion about their decision, its moral implications and how it might affect their relationship and preparation for marriage. Moving in together is usually seen as a convenient way to solve financial difficulties and the need for intimacy and togetherness. Unfortunately, convenience is not a good motive on which to build moral decisions. (Did you know convenience is the primary motive for abortion? Abortion is seen as a convenient way to solve the problem of an unwanted pregnancy.) Many couples who move in together because it is convenient often move out (during courtship or marriage) because it is a convenient way to solve relational difficulties.

For 2,000 years the Christian church, guided by the Scriptures and the Holy Spirit, has consistently taught that living together is not the way to prepare for a Christian marriage. Do we think that God is now speaking a new word to our generation? I doubt it. Are couples who choose to follow the traditional teaching of Christ and the church "old-fashioned?" Only if one thinks that the Eternal Word of God has suddenly become old-fashioned in the late 20th Century.

Sexual intercourse is sometimes called the "language of love." In God's design, sexual intercourse belongs in the context of "committed love" and the possibility of "new life." So, from a Christian viewpoint, when two people make love they are saying to each other, "I love you today and I am committed to loving you in sickness and in health, in good times and in bad times and all the days of my life. And, if God blesses our love with new life, I am ready to care for that new life with you." That is the Christian meaning of genital intercourse. Often today, people try to rewrite its meaning to suit their own needs, e.g., "I love you today for the pleasure you give me, for the way you make me feel," or "I love you today, I hope I can love you tomorrow, but I don't want to make any commitments and please know that if you become pregnant, it's your responsibility." Sometimes we allow our bodies to say more than our hearts are ready or willing to give. When that happens our lovemaking is a lie however sincere it may seem.

Christian marriage is a wonderful vocation and it deserves the very best when it comes to preparation. Let us not toss aside 2,000 years of Christian wisdom for a modern trend that is being tried and already found wanting.