1 Corinthians 7:14

Is sanctified in the wife (hgiastai en th gunaiki). Perfect passive indicative of agiazw, to set apart, to hallow, to sanctify. Paul does not, of course, mean that the unbelieving husband is saved by the faith of the believing wife, though Hodge actually so interprets him. Clearly he only means that the marriage relation is sanctified so that there is no need of a divorce. If either husband or wife is a believer and the other agrees to remain, the marriage is holy and need not be set aside. This is so simple that one wonders at the ability of men to get confused over Paul's language. Else were your children unclean (epei ara ta tekna akaqarta). The common ellipse of the condition with epei: "since, accordingly, if it is otherwise, your children are illegitimate (akaqarta)." If the relations of the parents be holy, the child's birth must be holy also (not illegitimate). "He is not assuming that the child of a Christian parent would be baptized; that would spoil rather than help his argument, for it would imply that the child was not agio till it was baptized. The verse throws no light on the question of infant baptism" (Robertson and Plummer).