12 But to the rest I say, and not the Lord; If a brother has a wife who is not a Christian, and it is her desire to go on living with him, let him not go away from her. 13 And if a woman has a husband who is not a Christian, and it is his desire to go on living with her, let her not go away from her husband. 14 For the husband who has not faith is made holy through his Christian wife, and the wife who is not a Christian is made holy through the brother: if not, your children would be unholy, but now are they holy. 15 But if the one who is not a Christian has a desire to go away, let it be so: the brother or the sister in such a position is not forced to do one thing or the other: but it is God's pleasure that we may be at peace with one another.
Matthew Henry's Commentary on 1 Corinthians 7:12-15
Commentary on 1 Corinthians 7:10-16
(Read 1 Corinthians 7:10-16)
Man and wife must not separate for any other cause than what Christ allows. Divorce, at that time, was very common among both Jews and Gentiles, on very slight pretexts. Marriage is a Divine institution; and is an engagement for life, by God's appointment. We are bound, as much as in us lies, to live peaceably with all men, Romans 12:18, therefore to promote the peace and comfort of our nearest relatives, though unbelievers. It should be the labour and study of those who are married, to make each other as easy and happy as possible. Should a Christian desert a husband or wife, when there is opportunity to give the greatest proof of love? Stay, and labour heartily for the conversion of thy relative. In every state and relation the Lord has called us to peace; and every thing should be done to promote harmony, as far as truth and holiness will permit.