Thou shalt not commit adultery. – Exodus 20:14

Genesis 2:20-24

²⁰ And Adam gave names to all cattle, and to the fowl of the air, and to every beast of the field; but for Adam there was not found an help meet for him.

²¹ And the Lord God caused a deep sleep to fall upon Adam, and he slept: and he took one of his ribs, and closed up the flesh instead thereof;

²² And the rib, which the Lord God had taken from man, made he a woman, and brought her unto the man.

²³ And Adam said, This is now bone of my bones, and flesh of my flesh: she shall be called Woman, because she was taken out of Man.

²⁴ Therefore shall a man leave his father and his mother, and shall cleave unto his wife: and they shall be one flesh.

1 Corinthians 6:16-18

¹⁶ What? know ye not that he which is joined to an harlot is one body? for two, saith he, shall be one flesh.

¹⁷ But he that is joined unto the Lord is one spirit.

¹⁸ Flee fornication. Every sin that a man doeth is without the body; but he that committeth fornication sinneth against his own body.

Matthew 5: 27-32

²⁷ Ye have heard that it was said by them of old time, Thou shalt not commit adultery:

²⁸ But I say unto you, That whosoever looketh on a woman to lust after her hath committed adultery with her already in his heart.

²⁹ And if thy right eye offend thee, pluck it out, and cast it from thee: for it is profitable for thee that one of thy members should perish, and not that thy whole body should be cast into hell.

³⁰ And if thy right hand offend thee, cut it off, and cast it from thee: for it is profitable for thee that one of thy members should perish, and not that thy whole body should be cast into hell.

³¹ It hath been said, Whosoever shall put away his wife, let him give her a writing of divorcement:

³² But I say unto you, That whosoever shall put away his wife, saving for the cause of fornication, causeth her to commit adultery: and whosoever shall marry her that is divorced committeth adultery.

Matthew 19:3-12

³ The Pharisees also came unto him, tempting him, and saying unto him, Is it lawful for a man to put away his wife for every cause?

⁴ And he answered and said unto them, Have ye not read, that he which made them at the beginning made them male and female,

⁵ And said, For this cause shall a man leave father and mother, and shall cleave to his wife: and they twain shall be one flesh?

⁶ Wherefore they are no more twain, but one flesh. What therefore God hath joined together, let not man put asunder.

⁷ They say unto him, Why did Moses then command to give a writing of divorcement, and to put her away?

⁸ He saith unto them, Moses because of the hardness of your hearts suffered you to put away your wives: but from the beginning it was not so.

⁹ And I say unto you, Whosoever shall put away his wife, except it be for fornication, and shall marry another, committeth adultery: and whoso marrieth her which is put away doth commit adultery.

¹⁰ His disciples say unto him, If the case of the man be so with his wife, it is not good to marry.

¹¹ But he said unto them, All men cannot receive this saying, save they to whom it is given.

¹² For there are some eunuchs, which were so born from their mother’s womb: and there are some eunuchs, which were made eunuchs of men: and there be eunuchs, which have made themselves eunuchs for the kingdom of heaven’s sake. He that is able to receive it, let him receive it.

1 Corinthians 7:10-11

¹⁰ And unto the married I command, yet not I, but the Lord, Let not the wife depart from her husband:

¹¹ But and if she depart, let her remain unmarried or be reconciled to her husband: and let not the husband put away his wife.