In my last couple blog posts I have explained that the Bible tells us that Christians should not cause a separation or divorce process with their unbelieving spouses: they should continue being married to their unbelieving spouse if he or she still wants to be married to them. One reason they should remain married is because their marriage will have practical benefits for the unbeliever:
14 For the unbelieving husband is sanctified through his wife, and the unbelieving wife is sanctified through [h]her believing husband; for otherwise your children are unclean, but now they are holy. (I Corinthians 7:13-14 NIV)
The fact of the matter is that there are practical benefits for the unbeliever who has a believing spouse. They are “sanctified” by their believing wife or husband in the sense that the good behavior and gentle manner will rub off on them a little. More importantly, they will see the testimony of the godly spouse and therefore have a great opportunity to become believers themselves. Furthermore, there are practical benefits for the children as well, if their parents stay together. It is far better for the children to live with one believing and one unbelieving parent, then to be simply living with only one parent. Children of a single unbelieving parent are called “unclean.” This probably means that they are subject to more temptation and negative pressures. They are more likely to fall into sexual sins, and other problems because they do not have the benefit of both masculine and feminine influence in their home. Having at least one saved parent in the home helps make the children “holy,” in the sense that it exposes them to the ways of the Lord, and gives them an opportunity to become a Christian themselves.
None of this means that a child or a spouse can be saved simply by virtue of a family members’ faith. Salvation is personal: each individual must believe for themself in order to be saved. But the godly influence of a mother, wife, or husband, can certainly influence them to choose Christ.