If a man is found lying with the wife of another man, both of them shall die, the man who lay with the woman, and the woman. So you shall purge the evil from Israel.
(Deuteronomy 22:22) ESV

When a man takes a wife and marries her, if then she finds no favor in his eyes because he has found some indecency in her, and he writes her a certificate of divorce and puts it in her hand and sends her out of his house, and she departs out of his house, and if she goes and becomes another man's wife, and the latter man hates her and writes her a certificate of divorce and puts it in her hand and sends her out of his house, or if the latter man dies, who took her to be his wife, then her former husband, who sent her away, may not take her again to be his wife, after she has been defiled, for that is an abomination before the Lord. And you shall not bring sin upon the land that the Lord your God is giving you for an inheritance.
(Deuteronomy 24:1-4) ESV

So you will be delivered from the forbidden woman, from the adulteress with her smooth words, who forsakes the companion of her youth and forgets the covenant of her God; for her house sinks down to death, and her paths to the departed; none who go to her come back, nor do they regain the paths of life.
(Proverbs 2:16-19) ESV

For the lips of a forbidden woman drip honey, and her speech is smoother than oil, but in the end she is bitter as wormwood, sharp as a two-edged sword. Her feet go down to death; her steps follow the path to Sheol; she does not ponder the path of life; her ways wander, and she does not know it. And now, O sons, listen to me, and do not depart from the words of my mouth. ...
(Proverbs 5:3-22) ESV

To preserve you from the evil woman, from the smooth tongue of the adulteress. Do not desire her beauty in your heart, and do not let her capture you with her eyelashes; for the price of a prostitute is only a loaf of bread, but a married woman hunts down a precious life. Can a man carry fire next to his chest and his clothes not be burned? Or can one walk on hot coals and his feet not be scorched? ...
(Proverbs 6:24-29) ESV

He who commits adultery lacks sense; he who does it destroys himself.
(Proverbs 6:32) ESV

For a prostitute is a deep pit; an adulteress is a narrow well.
(Proverbs 23:27) ESV

But I say to you that everyone who looks at a woman with lustful intent has already committed adultery with her in his heart.
(Matthew 5:28) ESV

And I say to you: whoever divorces his wife, except for sexual immorality, and marries another, commits adultery.
(Matthew 19:9) ESV

Everyone who divorces his wife and marries another commits adultery, and he who marries a woman divorced from her husband commits adultery.
(Luke 16:18) ESV

Accordingly, she will be called an adulteress if she lives with another man while her husband is alive. But if her husband dies, she is free from that law, and if she marries another man she is not an adulteress.
(Romans 7:3) ESV

Let us walk properly as in the daytime, not in orgies and drunkenness, not in sexual immorality and sensuality, not in quarreling and jealousy.
(Romans 13:13) ESV

Flee from sexual immorality. Every other sin a person commits is outside the body, but the sexually immoral person sins against his own body.
(1 Corinthians 6:18) ESV

We must not indulge in sexual immorality as some of them did, and twenty-three thousand fell in a single day.
(1 Corinthians 10:8) ESV

Love is patient and kind; love does not envy or boast; it is not arrogant or rude. It does not insist on its own way; it is not irritable or resentful; it does not rejoice at wrongdoing, but rejoices with the truth. Love bears all things, believes all things, hopes all things, endures all things.
(1 Corinthians 13:4-7) ESV

For you may be sure of this, that everyone who is sexually immoral or impure, or who is covetous (that is, an idolater), has no inheritance in the kingdom of Christ and God.
(Ephesians 5:5) ESV

Husbands, love your wives, as Christ loved the church and gave himself up for her,
(Ephesians 5:25) ESV

Let marriage be held in honor among all, and let the marriage bed be undefiled, for God will judge the sexually immoral and adulterous.
(Hebrews 13:4) ESV¹