1 Corinthians 7:14 – Sanctified spouses, holy children

1 Cor 7:14 – ‘The unbelieving husband is sanctified because of the wife, and the unbelieving wife because of her husband. Otherwise your children are unclean, but now they are holy.’
What is the meaning of ‘sanctified’ and ‘holy’ in this verse? Several options may be considered:-
1. That it is about the regeneration of the unbelieving partner. According to this view, Paul would be stating that the unbelieving spouse has become regenerate through the believing partner. But, notwithstanding Scripture’s greater emphasis on corporate, family-based faith compared with our own more individualistic approach, this interpretation fails to take account of the still greater emphasis on the need for personal faith. As Ciampa and Rosna remark, Paul cannot be referring to the actual conversion/regeneration of the unbelieving partner, since 1 Cor 7:16 shows that this can only be a hoped-for consequence later on in the marriage.
2. That it is about the influence of the believing partner. Paul may have a mind a kind of ‘holiness by association’, as is taught in Ex 29:37. Many commentators echo the thought of Calvin: ‘The godliness of the one does more to “sanctify” the marriage than the ungodliness of the other to make it unclean.’ This is in contrast to Paul’s teaching in 1 Cor 6:15-17, where a man has sexual relations with a prostitute. In the words of Garland: ‘A Christian who has relations with a prostitute cannot convey holiness, because that union is outside the will of God. Fornication is the antithesis of holiness. Marriage, on the other hand, is a divine institution that accords with God’s will for man and woman.’
Ciampa and Rosna would agree with Calvin, writing: ‘The notion that holiness rather than uncleanness is contagious has only marginal biblical support (cf. Exod. 29:37; 30:29; Lev. 6:18) prior to the ministry of Jesus. When Jesus touched unclean people, however, rather than becoming unclean himself his own holiness proved to be contagious, making the unclean clean (e.g., Mark 1:40–44//Matt. 8:2–3//Luke 5:12–14; Mark 5:25–34, 39–42). So also in Paul’s view, perhaps due to the example of Jesus, holiness is more powerful than impurity, at least the holiness that comes through Christ’s sanctifying work.’
For John Murray, it would seem that this sanctification is clearly not a transformation into Christlikeness, but ‘the sanctification of privilege, connection and relationship.’
‘The spouse’s example, witness, prayer, and living out of the gospel make the spouse and the children in this sense holy.’ (Thiselton)
‘“Sanctified” and “holy” cannot here mean “saved,” as verse 16 proves. Rather they refer to “the moral and spiritual impact of the life of the believer” on the rest of the family, making those other family members “set apart in a very special place … as God’s object of devotion.”’ (Blomberg, quoting Patterson)
Schreiner: ‘When Paul speaks of children being holy and unbelieving spouses sanctified, he likely means that the presence of believers in a family places the family in a holy sphere, which gives unbelievers the possibility of salvation.’ (Paul: Apostle of God’s Glory in Christ)
This interpretation – the most common among commentators – suffers because Paul does not treat holiness as a future possibility here, but rather as an actuality. Paul does not say, ‘might be sanctified’, but ‘has been sanctified’.
3. That it is about the legitimacy of the marriage. In this interpretation, Paul is talking about making the marriage pure in the eyes of God, and therefore indissoluble. The doctrine of ‘becoming one flesh’ transcends even the question of whether the two partners in the marriage share a saving faith in Christ.
John Piper quotes Paul Jewett: Paul has in view the sanctity of lawful matrimony and the purity of the resulting offspring. When he says that the unbeliever is “sanctified” by the believer, he is simply referring to the marriage covenant by which the unbeliever has been consecrated and set apart for the exclusive fellowship of the believer in the bond of marriage. He writes to assure his Corinthian converts that this exclusive propriety, which the marriage covenant seals, is in no way abrogated by any disparity of religious commitment, great as this disparity may be. Christians, then, should never fear defilement through cohabitation with an unbelieving spouse: indeed, such defilement would imply that their children were also defiled, which they grant is not the case. In other words, he reasons from what is allowed to what is in doubt. If that relationship were unclean from which the children came, then the children would be unclean too; but everyone agrees they are not. Rather, they are “holy” in the sense that they are not contaminated with the taint of illegitimacy. Therefore, the union of which they were born is likewise above suspicion and reproach. (Infant Baptism and the Covenant of Grace, 133)
Barnes: ‘all that we are required to understand here is, that the unbelieving husband was sanctified in regard to the subject under discussion; that is, in regard to the question whether it was proper for them to live together, or whether they should be separated or not. And the sense may be, “They are by the marriage tie one flesh. They are indissolubly united by the ordinance of God. As they are one by his appointment, as they have received his sanction to the marriage union, and as one of them is holy, so the other is to be regarded as sanctified, or made so holy by the divine sanction to the union, that it is proper for them to live together in the marriage relation.”’
Paul’s statement about children has, similarly, attracted various interpretations:-
1. Some think that it refers to the regeneration of the children.
2. Others consider that Paul is thinking about the influence for good of the believing parent on the children. ‘Presumably this means that the children, in coming under the influence of one Christian parent, are within the sphere of God’s love and the power of the gospel, not that they are automatically Christians’ (Wright). ‘They are considered undefiled by paganism if at least one of their parents is a Christian.’ (EDBT)
3. Still others think that it refers to the legitimacy of the family unit. ‘In 1 Corinthians 7:14, Paul resolves the question of whether God accepts a marriage in which only one partner has become a Christian by invoking the certainty that the children of such a marriage are relationally and covenantally “holy,” that is, are dedicated to and accepted by God in company with their one Christian parent. So the principle of parent-and-child solidarity still stands, as Peter also indicated in his Pentecost sermon (Acts 2:39). But if infants share covenant status with their parent, it is fitting, other things being equal, to give them the sign of that status and of their place in the covenant community, and it would be unfitting for the church to withhold it. This fitness is demonstrated by the fact that when circumcision was the sign of covenant status and community inclusion, God commanded it explicitly (Gen. 17:9–14).’ (Packer, Concise Theology)