1 Corinthians 7:10-12

10 These are my instructions to those who are married—in fact not from me but the Lord: The wife should not leave her husband

11 (or if she does, she should not re-marry, or she should return to her husband); and the husband should not leave his wife.[25]

12 Now, to the rest of you, (and this is me speaking, not the Lord), I would say, “If a Christian man has a non-Christian wife and she is willing to stay with him, he should not leave her.