John 4:18
"for you have had five husbands, and the man you have at present is not your husband. You have spoken the truth in saying that."
Mark 10:12
and if a woman puts away her husband and marries another man, she commits adultery."
Romans 7:3
This accounts for the fact that if during her husband's life she lives with another man, she will be stigmatized as an adulteress; but that if her husband is dead she is no longer under the old prohibition, and even though she marries again, she is not an adulteress.
1 Corinthians 7:10-11
But to those already married my instructions are--yet not mine, but the Lord's--that a wife is not to leave her husband;
Hebrews 13:4
Let marriage be held in honour among all, and let the marriage bed be unpolluted; for fornicators and adulterers God will judge.