(1 Cor. 7:14) What does sanctified mean here?

CLAIM: Paul claims that non-believing people can be “sanctified.” What does he mean by this?

RESPONSE: The Greek word for “sanctified” (Greek hagiazo) literally means “to be set apart.” Therefore, Paul doesn’t mean that unbelievers can grow spiritually (i.e. the normal use of sanctification). Instead, he means that these people will be specially set apart by God. In other words, God will bring extra conviction and attention on a household with only one believer in it.