In the time of Ezra, Jewish men who had married pagan wives were told to send these wives and their children away, in obedience to the law of God (Ezra 10:3).
The same does not apply to New Testament believers, however. It is not wrong for a believer to stay married to an unbeliever, since the unbelieving spouse is made holy
because of the believing spouse. As a result, the children that come from such a marriage are also holy.
Paul uses the word holy
as a synonym for clean
(see 1 Corinthians 7:14b). His argument that unbelievers are made holy through their believing spouses stands in striking contrast to Old Testament purity laws (see Haggai 2:11–13).
To be made holy
means to be set apart for God. The unbelieving spouse is made holy because of his (or her) one-flesh union with the believer (see 1 Corinthians 6:16). He comes into the circle of God’s people, where he is brought close to the gospel of salvation. God lays claim to his life.
This does not mean that the unbelieving spouse is saved. As 1 Corinthians 7:16 intimates, salvation is something that the unbelieving spouse must accept through faith in the gospel.
Interestingly enough, there are no references to children in this chapter, except for the brief comment in this verse. The children’s holiness (like the holiness of their unbelieving parent) is a status that has been given to them, on account of their believing parent’s union with Christ.
14 For the unbelieving husband is made holy because of his wife, and the unbelieving wife is made holy because of her husband. Otherwise your children would be unclean, but as it is, they are holy.