The following post was first an email to a young church planter seeking counsel. He is planting a church in a rough area. Not a few of those who are getting converted have been living together, sometimes with children, sometimes for years, without getting married. His question, then, is what should be said to these couples where one of the pair gets converted, and the other, so far, does not. Should the advice be to get married? Or is that encouraging people to be unequally yoked?
The question you're facing is really about what marriage is, according to the Bible. At various times, I've faced the same questions you are now facing. The following are some guidelines. Some of these depend directly on what the Bible says, and some belong in the domain of prudential wisdom that is itself shaped by the Bible.
(1) In the Bible, marriage is more than sexual union between a man and a woman, but it is not less. It also includes public commitment to each other in some public, legal, and culturally acknowledged way that sets this pair apart as husband and wife. In the nomadic culture of Abraham's day, a part of the ceremony was for the groom to take his bride “into his mother's tent” (so Isaac)—that was the equivalent of the wedding night. Under the law of Moses, if A and B sleep together, and if it is clearly not rape, the law does not say, “Oh, well, I guess that makes them married.” No, the dowry must still be paid (that was part of the public declaration of marriage under that culture), the two families are involved, etc. So today, if A & B have been living together in sexual intimacy for some time, but without benefit of public attestation (whether in a church or before, say, a justice of the peace), they are not really “married” in the full sense of that term (the sexual union is there, but not the public mutual commitment according to the laws of our day); but equally, if A & B take vows of marriage and then don't sleep together, this is not fully “marriage” either.
(2) The right thing to do, in both cases, is usually (I can think of one or two difficult exceptions!) to finalize the other part. It is not to try to undo what has already been done! One cannot “undo” this sustained sexual, common-law, union. Thus to demand that a couple tear themselves apart after they've been living together for, say, five years, with perhaps a child or two, simply won't do. What needs to be urged upon them is that they get “married” legally—i.e., publicly, according to the cultural standards of the state.
(3) But, someone asks, suppose that B has become a Christian, and A is still an unbeliever: isn't going ahead with (the legal part of) marriage in danger of making them unequally yoked together? In response: (a) If A and B were fully married (i.e., legally, and in sexual consummation) when they were both unbelievers, and then one of them became a Christian, we would not say that this means they should break up. In fact, in 1 Cor. 7 Paul explicitly tells the Christian partner in such cases not to leave. Indeed, the Christian spouse is to be exemplary in conduct and grace, in the hope of winning over his or her family. The prohibition of being unequally yoked together, when applied to marriage, envisages two people who are not married in any sense. But if one person in a marriage of two pagans becomes a Christian, Paul never applies the “don't be unequally yoked” command to break up a marriage that is already in place. In fact, as we see in 1 Cor. 7, quite the reverse. (b) So what's the difference if A & B are simply living together, but not legally married? The difference, of course, is that they are not fully married as the Bible sees marriage; but they have well and truly started the process! They cannot undo what has been done. To pretend otherwise is foolish. The way ahead is to encourage the completion of the process, not the undoing of what cannot be undone.
(4) In most cases, the unbelieving partner will go along with this plan, if the matter is approached graciously, wisely, humbly. If not, then a new set of questions arises that is not addressed in your email.
(5) You may remember that in my first point, above, I included the options “whether in a church or before, say, a justice of the peace.” When A and B are both Christians, it is normal, in this country, for them to get married in a church, and then we speak of a Christian wedding. But it is important to see that, strictly speaking, marriage (despite the Roman Catholic Church) is not a sacrament to be reserved for Christians. It is a creation ordinance—that is, it is part of the plan of creation itself, something that God has ordained for man/woman pairs everywhere, not something that flows out of the life of the church and that belongs only to Christians.
In France, for example, all marriages must be performed before a civil authority. I see no objection to that; in fact, I think it is a good thing (even if it arose in France for bad reasons), for it clarifies issues. In France, where A and B are Christians, they will get married before the local civil authority, and then have a separate ceremony within the congregation—a ceremony that has no culturally-defined legal standing, but becomes an opportunity to remember how the gift of God that we call marriage is elevated and transformed when put within the framework of the gospel. We learn, for instance, of its typological connection with Christ and the church; we learn that apostasy and adultery have similar roots and condemnations; we learn that God himself dares to speak of the marriage supper of the Lamb; we are reminded of God's wise provision of marriage, of the place and importance of children reared in the nurture and admonition of the Lord, and so on.
In America (and most Anglo-Saxon countries), when a marriage takes place within a congregation (and usually in a church building), the minister officiating is acting partly as a minister of the gospel and partly as a licensed official of the state. That is why it is not legal for anyone who chooses to do so to officiate: there must be some sort of legal standing. Fair enough; I can live with that. But my point in the case you are talking about must not be hung up on whether the legal marriage ceremony takes place in a church building under the jurisdiction of a minister, or under the jurisdiction of a justice of the peace. It will be clear by now that I do not think the minister is sinning if he legally joins A and B together, where they have been living together for some time and where one of the two has now become a Christian. But equally, if the unbeliever in this case is willing to get married, but not within the context of the church, fine—encourage them to get married, and be sure you attend the ceremony and applaud them. There does not have to be a minister in order to be “done” properly. We have no interest in preserving the vestiges of medieval Catholic theology of marriage.
(6) Earlier I mentioned a couple of exceptions. Let me take up only one. Suppose A and B are 19 and 18 years of age respectively. Suppose they have both been sleeping around for some time. Suppose B now becomes a Christian. Is she (or he) now morally obligated to marry the last person she (or he) has been with? I doubt it. What is required is the kind of deep repentance that turns from such sin and pledges celibate living until genuine marriage. Obviously you could then conjure up hard cases where you are uncertain if what you are facing is one of these exceptions or not. If the principles are clear, a great deal of prudential wisdom may nevertheless be required in the application of the principles.
I hope these reflections help. If you need to follow up with me, please do not hesitate to do so.