To the married I give this command (not I, but the Lord): A wife must not separate from her husband. But if she does, she must remain unmarried or else be reconciled to her husband. And a husband must not divorce his wife.
But if the unbeliever leaves, let it be so. The brother or the sister is not bound in such circumstances; God has called us to live in peace.
-I Corinthians 7:10-11, 15, NIV
A very perplexing stance I hear in regards to divorce and remarriage is the one that allows for divorce but not remarriage as it comes to an abandoning unbelieving spouse.
Why bother with getting divorced then? One can remain legally separated and receive all the benefits of being apart from a destructive partner in that state.
Divorce allows one to remarry. That is the important difference between a legal separation and a divorce. Bigamy is usually illegal.
Plus, looking at the most pertinent text on abandonment (I Corinthians 7:10-15), it is an odd interpretation that suggests the believing spouse is still bound to treating the abandoning spouse as his or her husband. In what sense is that “free”?!
Passage highlights another reason why I do not encourage a faithful spouse to “fight for their marriage” with a cheater:
We are not to war against an unbelieving spouse who refuses to stay in a godly marriage. The opposite of fighting for one’s marriage is taught here (vv15) by Paul in regards to an unbelieving spouse walking away. The Apostle Paul teaches us to let them go without a fuss!
The whole idea of being “not bound” in contrast to other circumstances where Paul explicitly prohibits remarriage is to communicate to us that remarriage is a real possibility for the abandoned Christian. That is what the context and contrast ought to teach a careful Bible student.
If the Apostle Paul viewed this situation of an abandoning unbeliever like a separation situation, he would have just reiterated his teaching from verse eleven prohibiting remarriage and divorce. He didn’t. Instead, he taught that the abandoned spouse is free of such bonds as mentioned earlier–i.e. do not divorce and do not remarry.