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 man has been sanctified by her. I Corinthians 7:13-14 NIV
This passage does not mean that the husband has become a child of God, which only happens through faith in the sacrifice of our Lord Jesus. However, it suggests that there are blessings for the husband in being married to a Christian. He will be encouraged to read the Bible, to go to church, to pray. Maybe, eventually, his heart will be open to the love of God. Perhaps feeling the love of his wife will make him realize that her care for him not only comes from natural affection, but also from the supernatural gifts of love that God gives us.
We are also reminded that a Christian is not tainted by being with an unbeliever, rather the unbeliever is influenced by the believer. Our eternal life with Jesus is sealed and we are protected from the effects of the world on our souls. As Christians we can pray for walls of protection around any family or friends who are not believers. They may never know what misery they have been saved from because of the prayers of their family and friends. Sometimes unbelievers don’t want to hear the Good News but Christians can still be praying and showing godly character. The sweet fragrance of their lives can only be a blessing. It may be uncomfortable for the unbeliever if conviction of sin starts to happen, but that is the first step to salvation.