I Corinthians 7:10-11, 15

Now to the married I command, yet not I but the Lord: A wife is not to depart from her husband. But even if she does depart, let her remain unmarried or be reconciled to her husband. And a husband is not to divorce his wife.

But if the unbeliever departs, let him depart; a brother or a sister is not under bondage in such cases. But God has called us to peace.