If your spouse leaves the marriage it can be a devastating time. Sometimes they may want to get a divorce and bring papers for you to sign. But God says we are not to divorce an unbelieving spouse. In marriage, even if only one spouse is a believer, God says the marriage is sanctified and set apart for His purpose. According to the state you are divorced, but according to God you are still married.
If any brother has a wife who is not a believer and she is willing to live with him, he must not divorce her. And if a woman has a husband who is a believer and he is willing to live with her, she must not divorce him. For the unbelieving husband has been sanctified through his wife, and the unbelieving wife has been sanctified through her believing husband. 1 Corinthians 7:12-14 NIV
God’s ideal is for couples to stay together and try and make the marriage work. The believing spouse should try and bring the wayward spouse to Jesus Christ. Since God does regard your marriage as sanctified by the presence of just one believing spouse, the believing spouse should do what they can to help the unbelieving spouse come into the light and accept Christ.
But if the unbeliever leaves let him do so. A believing man or woman is not bound in such circumstances. 1 Corinthians 7:15 NIV
The above verse is often misunderstood and misused in society. It is not a loophole for divorce. However, if the unbeliever insists on leaving the marriage, what can you do? Paul says we are to let him or her go. The only other choice would be to deny your own faith to preserve the marriage. The message here is that couples are to seek harmony if at all possible. He does not want us to seek out ways to divorce or separate from our spouse.
God wants the believing spouse to work with the unbelieving spouse if it does not compromise his or her own faith and beliefs. Not bound in such circumstances does not mean it is okay to divorce your unbelieving spouse. It means that you are not bound to try and make the unbelieving spouse stay with you if it is going to compromise your beliefs in the process.
You cannot make an unbelieving spouse stay in the marriage. But there are a few things you can do to help them to see their erring ways, and come to Christ. Be an example to the unbelieving spouse. Being a good influence has far greater spiritual power than you think.
Therefore, strengthen your feeble arms and weak knees. Make level paths for your feet, so that the lame may not be disabled, but rather healed. Hebrews 12:12,13 NIV
Believers have a responsibility to the marriage if they are truly living for Christ, as they claim to be. Your example should make it easier for your spouse to believe in and follow Jesus. If your example makes the unbelieving spouse confused and misled, they will not see Jesus in you. Sometimes you might not feel well enough spiritually or emotionally to be a good example for your spouse, and this is why you need to always stay focused on Christ for your own strength and comfort. Then you can use that strength to help the unbelieving spouse find their way back home again where they belong.
Make every effort to live in peace with all men and to be holy; without holiness no one will see the lord. Hebrews 12:14 NIV
Pray constantly for the unbelieving spouse. Let them see their erring ways not by what you say to them but by how you live your own life. In many instances it is good to bring their erring ways to their attention in a good way so as to restore him or her to God. Don’t talk the self-righteous story with them by telling them how sinful or rotten they are. Don’t say you are a Christian and they are not. This kind of behavior will make them run from you as fast as they can.
“If your brother sins, rebuke him, and if he repents, forgive him. If he sins against you seven times in a day, and seven times comes back to you and says, ‘I repent,’ forgive him.” Luke 17:3,4 NIV
Last but not least, and I think this is very important, do not allow the unbelieving spouse to take advantage of your good graces and mercy. There will be times you will need to detach from them and you can do this in a loving way. If they are doing something that goes against your conscience, do not be a part of it or allow it to carry on in your presence. Be humble but strong. Be discerning but compassionate. Be careful that the unbeliever does not bring you down with them. Always stay focused on the Lord and He will keep you protected and strong in your time of suffering and need.
Whether you turn to the right or to the left, your ears will hear a voice behind you, saying, “This is the way; walk in it.” Isaiah 30:21 NIV