1 Corinthians 7:10-12
New International Version
10 To the married I give this command (not I, but the Lord): A wife must not separate from her husband.(A) 11 But if she does, she must remain unmarried or else be reconciled to her husband.(B) And a husband must not divorce his wife.
12 To the rest I say this (I, not the Lord):(C) If any brother has a wife who is not a believer and she is willing to live with him, he must not divorce her.Read full chapter