Is Christian Dating Incestuous? What’s Weird, Wrong, and Good about the “Sibling Rule”

Why It’s Weird

 The Christian dating experience is terribly awkward. Yet somehow (surprisingly), Christians have figured out a way to make it even worse. We have taken the beautiful doctrine of adoption and made dating basically unbearable by pushing Christian brother-sister language. “You what? She’s your sister, man.” Thanks. Things weren’t weird enough.

Let’s call this advice “the sibling rule,” taken from Paul’s advice in 1 Timothy 5:2 to treat “younger women as sisters, in all purity.” “Treat her like your blood sister” is a saying that is often used to encourage strong physical boundaries between dating singles in the church. And, while it is trendy and slings a verse that seems straightforward in a sound-bite-theology world, something doesn’t sit right about the rule.

Isn’t it strange to regulate the Christian dating process by making it quasi-incestuous? The sibling rule is an attempt to make the idea of premarital sexuality seem gross. And yet, God isn’t disappointed in you for having feelings for a girl that aren’t appropriate in a blood sibling relationship. In fact, God delights in you having feelings for a girl that is your “sister in Christ” that wouldn’t be appropriate for your sister. And he is not disappointed in you for acting on them. To say anything otherwise is a misuse of the beautiful reality that we are co-heirs of God with Christ and the whole church (Rom. 8:17), which provides the context for romance to eventually blossom into that which truly pictures our relationship with Christ (Greek of 1 Cor. 9:5; 1 Tim. 1:5). Christian dating is not spiritual incest, for several reasons.

Why It’s Wrong

 First, the sibling rule can’t accommodate sexuality. The biblical understanding of the sister-brother relationship isn’t meant to destroy sexuality. And yet, it is often used to discourage any form of premarital sexual expression. A relationship that contains sexual expression—i.e., the husband-wife relationship—does not dissolve the Christian sister-brother relationship (Mark 3:35; 1 Cor. 12:27; Eph. 5:1, 8, 22-23). In fact, without being brother and sister in Christ, spouses cannot have a healthy Christian marriage. A biblical conception of the spiritual sister-brother relationship motivates sexual purity in different forms among both married and non-married couples on the basis of each honoring the other as a Christian, who is a spiritual sibling, fellow soldier, saint, and friend. But the basic point is that to set up the brother-sister relationship against sexuality carte blanche is a misuse of both realities.

Second, the sibling rule can’t accommodate the whole person. Surely you’ll never hear the advice, “Relate to her emotionally like you’d relate to your blood sister.” The dating relationship requires emotional and relational realities and boundaries that neither the sibling rule nor the marriage relationship can fit. It is truly a unique kind of relationship. The sibling rule forces rigid constructs physically that it can’t apply consistently to the whole person.

Third, the sibling rule can’t accommodate romantic growth. The category shift between sister and wife, if conceived as a light switch between nonsexual and sexual, is too vulgar to allow the things that most Christians naturally accept as healthy desire in the dating context. If a man confessed lust for his blood sister to the Apostle Paul, the least of the Apostles probably would have had serious concerns (1 Cor. 5:1-2). If a man confessed lust for a sister in Christ, the Apostle Paul probably would have referred him to a good price on a princess cut engagement ring (1 Cor. 7:9).

Now, naturally, we should not insist on a sexual dating that mirrors its emotional counterpart. We must encourage self-control (Prov. 25:28; 2 Pet. 1:6). But we should seek to conceive of the sexuality that exists in a dating relationship in terms of a reality that brings together organic relational growth and holistic personhood, without forcing a certain timeline (fast or slow) into overly rigid categories that unbalance the person and the relationship.

Why It’s Good

 Of course, Christian men and women are brothers and sisters in Christ, and that reality is as unchangeable as Christ’s own sonship (Rom. 1:3; 8:17).

So, what does it look like to have romantic feelings for your “sister”? The answer is just “No.” By analogy, when someone is experiencing an intense suffering, and someone starts talking to that person about repentance, there is a category error made. Repentance isn’t the most relevant category for suffering. It is because of union with Christ that we suffer, most basically (Col. 1:24; 1 Pet. 4:13); repentance may not always be the best go-to category for understanding suffering. Sometimes it is, but not systematically or foundationally.

Likewise in dating. She is your “sister,” but we shouldn’t import all the details of that metaphor into every aspect of our dating relationship. It’s just not the most relevant category for understanding who your girlfriend/boyfriend is to you. To relate like a sister means to honor, to respect, and to protect, but in the context of dating, to extend the metaphor to abolish any hint of premarital sexual expression is stretching the text of 1 Timothy 5:2. That doesn’t mean it’s okay to have sex before marriage; it’s not. But there is a legitimate future-wife-but-not-engaged category that, while requiring the spiritual brother-sister relationship in order to be a healthy Christian dating relationship, is not the sibling category per se.

What’s the point? Date her! Date him! Be romantic. Fall in love. Get all mushy, or whatever. Whatever you do, know that it’s okay. It’s not weird or “unchristian” (or sinful) to have romantic, intimate, and even sexual feelings for a Christian of the opposite sex who is not your spouse. Those feelings are natural, even preferable, to exist in the pursuit.

Again, Paul’s logic: Struggling to keep it in your pants together? Marry (1 Cor. 7:36). What does marriage look like? Spending so much time sacrificially serving each other’s needs that you don’t have time for much else (1 Cor. 7:33-34), and he’s probably not thinking primarily about sex there. 1 Corinthians 7 is Paul’s attempt to negotiate the intense interpersonal desires—emotional, personal, relational, and sexual—that arise in a romantic context with a view of the person that ideally balances all of those forms of intimacy in a robust conception of personhood.

So is Christian dating incestuous? It doesn’t have to feel that way. And in its best forms, it won’t, because it isn’t incestuous. The best way to use 1 Tim. 5:2 is allow it to make room for romance, so that when a dating couple becomes a married one, they can take with them the same brother-sister theology that they had as a dating couple, but more dynamically expressed in the context of marriage, which includes sexuality.