Christ gave instruction about the unbreakable and sacred nature of the marriage tie (see Matt. 19:4-6, 9). Paul deals here with cases concerning which no explicit teaching was given by Jesus, hence the expression, “speak I, not the Lord.” He was moved by the Holy Spirit in giving the counsel that follows, but he did not base his words on any previously recorded statement that Jesus had made (cf. on 1 Cor. 7:10).

 The duties of the unmarried persons in the church have been dealt with, particularly in connection with the question whether it is right and advisable for them to marry (see vs. 1-9). Similarly, the Lord’s command regarding married believers has been clearly stated, also how they should relate themselves to the questions of separation and divorce (see vs. 10, 11). Now the discussion turns to cases in which one party is a Christian and the other is not. The issue is raised: Would a voluntary separation be advisable and proper under such circumstances? The believing husband or wife might not desire to remain in intimate contact with a heathen companion. Counsel for such cases is given.

There might be instances in which a non-Christian wife would be so antagonistic to the gospel, and so violent in her opposition, that she would not wish to live with her Christian husband. In such cases the husband could not prevent the separation. If, on the contrary, the unbelieving wife desired to remain with her believing husband, he is not at liberty to seek a separation. The marriage vow is sacred, and cannot be set aside by any change in the religious beliefs of either party. The only effect of the conversion of one party should be to make him or her more tender, kind, loving, and loyal than before. A marriage to an unbeliever is to be regarded as binding on a believer so long as the unbeliever does not voluntarily separate himself from his believing companion and enter into another marriage.