What does 1 Corinthians 7:14 mean?

Paul has instructed Christians who are married to unbelieving spouses not to divorce, if the unsaved spouse is willing to stay in the marriage.

By God's design, marriage is the most intimate of all human relationships (Genesis 2:24). Why, then, would a Christian man or woman imagine God desiring them to separate from their spouse? Perhaps the Christians in Corinth were concerned that being in union with an unbeliever would make them unclean in God's eyes. Would their unsaved spouse cause God to see them as being guilty of the sin and unbelief of their spouse?

Paul's answer is that the opposite is true. A Christian's unbelieving spouse and children are, instead, "made holy." This is true for both husbands and wives, but has to be carefully understood.

Paul is not saying a person's unbelieving spouse and children are eternally saved simply by being married to or parented by a Christian. Saving faith cannot be borrowed, inherited, or willed to someone else. Scripture's clear teaching is that individuals must come to faith in Christ on their own in order to receive the grace of God's forgiveness for sin (Matthew 10:34–36; 1 Corinthians 3:13; Galatians 6:3–5). Further, Paul writes in verse 16 that an unbeliever might be saved through the witness of a Christian spouse. That, in and of itself, proves that simply being married to a believer does not automatically bring eternal salvation to a non-Christian.

What Paul does seem to be saying is that God regards the unbelieving spouse and children of a Christian person as a holy spouse and children. This is precisely because the husband and wife are united as one, and one of them is united with Christ. In this life, on this side of eternity, they are included with the people of God who have been set-apart for His purposes.

The Christian is not stained by his or her non-Christian spouse; the non-Christian spouse, instead, becomes blessed by God so long as they remain married.