Hello! I have some questions about some passages in 1 Corinthians that I was hoping you could perhaps answer and bring some clarity to.
1 Cor 7:12-16
My question(s) specifically focuses on verse 14, where Paul says ‘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’ (ESV). I looked at the way the NIV renders this section as well and saw that they use the word ‘sanctified’ – does this sanctification/holiness reveal a salvation through associated family member (husband/wife passing it on to their children)? The concept of salvation being transferred or passed down seems kind of wrong, so am I just reading this wrong? Is the matter of holiness/sanctification separate from the matter of salvation? It seems like no certainty is given to whether the wife or husband will be able to save their non-believing spouse in verse 16, so is verse 14 unrelated to salvation/justification? Sorry, I’m all over the place!
Thanks for the question! Don’t feel too bad about your confusion with this passage, because you aren’t the only one who is perplexed by this rather puzzling text (I am as well).
Let’s examine this verse within its context and go further back a couple of verses to see what is going on:
To the rest I say this (I, not the Lord): 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 not 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. Otherwise your children would be unclean, but as it is, they are holy.
(1 Cor. 7:12-14 NIV)
The main contention here in the passage is the use of the term ‘sanctified’ (or holy) in the text here. Does the expression of this word within the context of this passage connote the idea that unbelieving spouses are saved and are made right with God primarily through their marital association with their respective Christian spouses? In what sense is the unbelieving husband or the unbelieving wife “sanctified”?
Let’s firstly do a quick etymology of the word “sanctified.” The word is also used interchangeably with the word “holy,” and there are two Greek grammatical forms of this word in the New Testament. The Greek noun for “sanctify” is “hagiasmos,” which is a word that carries the idea of making something holy or set apart. Similarly, its verb counterpart, “hagiazo,” also means “to set apart as holy, hallow, or to purify.”
So the whole concept of the word ‘sanctified’ (or ‘holy’) is to make a person or object sacred, to set it apart from all other things for special use. And we see this term used in various ways across the New Testament, and here are a few examples:
(1) In Hebrews 10:10, the writer tells us that as followers of Christ, “we have been made holy through the sacrifice of the body of Jesus Christ once for all.” God sets us apart from all others, so that we can be His people, those who have been cleansed completely of our sin. By Christ’s sacrifice, these Christians can now stand justified before God and draw near to His presence with full assurance (cf. Heb. 10:19-22). This is traditionally known as positional sanctification.
(2) In 1 Thessalonians 4:3, the apostle Paul writes that God’s will for every believer is for their sanctification; that they abstain from sexual immorality. By implication of this passage, God calls every Christian to grow in their godliness, constantly killing sin in their lives, and attaining to full spiritual maturity in Christ. This is generally known as progressive sanctification.
Knowing the various ways that this word can be used, this is where it would be helpful to set our theological parameters so that we know how verse 14 is to be interpreted in light of all of Scripture.
(1) What verse 14 cannot mean is that the unbelieving spouse is now justified before God through their marital association with their Christian spouse. The reason being is simple: (i) the fact that Paul makes a religious distinction between the spouses within that union as that of a ‘believer’ and an ‘unbeliever,’ makes it clear that Paul believes the unbelieving spouse is not saved; and (ii) the Scripture’s prominent teaching with regards to salvation is that a person is justified before God by faith in Christ alone, not by their association with any member of God’s community (whether that might be a spouse, brother, sister, father or mother, and so on). This is important to highlight because there is a tendency among people within our culture today who identify as being Christian, based on what their parents believe and follow in their household. We should eradicate the idea that salvation and Christian identity can be passed on like an heirloom within a family.
(2) What verse 14 also cannot mean is that the unbelieving spouse is growing in their godliness through the union of their Christian spouse. That too is bad theology, for at least 2 reasons: (i) we see that both Paul and Peter (or any other NT writer for the matter) never called unbelievers to grow in their godliness or to grow in their spiritual maturity in Christ. This exhortation of mortifying sin is a command given only to believers who are in right relationship with God. Instead, what we generally see through the New Testament is a call for unbelievers to repent of their sin and place their trust in the sufficient work of Jesus Christ for the atonement of their sin (see Mk. 1:15; Acts 2:38; 20:20-21). (ii) Growing in godliness and working on our sanctification is only made possible through our union with Christ (and not through our union with our spouses, no matter how godly they might be). John Hendryx states that “the principal means of the believer’s sanctification is union with Christ” . Christ is the source of the Christian’s spiritual vitality and it is only through Him that we are able to be transformed into his image (see. 1 Cor. 1:28-31; Phil. 2:12-13).
So then, what could this verse possibly mean? Paul was conscious of the reality that as the early church grew in numbers as the gospel was preached, there would arise situations within the church where members of the community have unbelieving spouses whom they married prior to their conversion – creating these sort of these seemingly ‘impure’ marriages where one spouse was a ‘believer’ and the other was an ‘unbeliever’. Believing spouses often felt the tension in their marriages, and wondered whether the union with their spouses defiled them, defiled Christ, and defiled their children. Others began to even ponder whether to divorce their unbelieving spouses in order to find and marry a Christian partner.
Paul was not about to make the cross of Christ the trademark for homewrecking. It would bring great disrepute to Christ and his gospel if Christian spouses were infamously known by their neighbours for destroying their marriages by leaving their pagan husbands and wives for other men and women of the faith. This is why Paul says in verse 12 that if “any brother has a wife who is not a believer and she is willing to live with him, he must not divorce her” (cf. 7:13). This marital union in no way defiles the believer or their children, “For the unbelieving husband has been sanctified through his wife, and the unbelieving wife has been sanctified through her believing husband” (7:14). What we see is the very opposite – the family home becomes set apart by the very presence of that Christian spouse. John Macarthur comments that “The sanctification is matrimonial and familial, not personal or spiritual.” . As mentioned before, this sanctification does not mean that the unbelieving spouse (or their children) are automatically saved by virtue of marriage, but it does mean that God blesses that particular household in a very special way. God radiates and extends His grace from that one believing individual into that home, where the pagan spouse and their children can experience the goodness and greatness of God through their godly character.
Johnny Mac describes it like this, “…it’s like when your wife gets a huge inheritance, and you have nothing to do with it. You aren’t even related to the people, but, man, do you cash in. It’s the same thing. You’re not even related to God, but you’re cashing in on the benefits that he’s pouring out on her. 
This sanctified household has access to the Word of God and has access to seeing God at work in transforming a person’s life for the better by the Word. What a blessing it is, then, for unbelievers to be married to Christians! And it is our hope that as these godly men and women magnify the goodness and greatness of God in their homes, their spouses will see their good deeds and glorify God by placing their trust in Jesus!
 – Monergism.com. (2020). Sanctification via Union With Christ | Monergism. [online] Available at: https://www.monergism.com/blog/sanctification-union-christ [Accessed 20 Feb. 2020].
 – Grace to You. (2020). A Sanctified Spouse. [online] Available at: https://www.gty.org/library/bibleqnas-library/QA0183/a-sanctified-spouse [Accessed 20 Feb. 2020].
 – Grace to You. (2020). Divine Guidelines for Marriage. [online] Available at: https://www.gty.org/library/sermons-library/1829/divine-guidelines-for-marriage [Accessed 24 Feb. 2020].