"Sanctified" in 1 Corinthians 7:14 does not mean saved; it describes the practical, behavioral influence a believing spouse has on an unbelieving one and on the children.

Mike argues biblical terms like "sanctification" are not always used in their systematic-theology sense. Here it describes curbing of sinful behavior: a godly spouse limits bad language, poor entertainment choices, etc., creating a positive moral environment for children. It is practical and pragmatic, not soteriological.