1 Corinthians 7:14-15

14For the unbelieving husband has been sanctified through his wife, and the unbelieving wife has been sanctified through her believing husband. Otherwise your children would be unclean, but as it is, they are holy. 15But if the unbeliever leaves, let it be so. The brother or the sister is not bound in such circumstances; God has called us to live in peace.