I’m not saying you are twisting scriptures to your liking @leasel -just hear me out, please.
In the Mosaic Law, adultery is most explicitly defined as sexual relations with another man’s wife. ~Leviticus 20:10 states that if a man commits adultery with his neighbor’s wife, both shall be put to death. That is the clearest legal definition in Torah. So you are correct that the Old Testament often frames adultery in terms of violating another man’s marriage covenant.
However, that is not the whole biblical picture.
The deeper principle of marriage is established in ~Genesis 2:24: “a man shall leave his father and mother and cleave unto his wife: and they shall be one flesh.” The pattern given is singular. One man, one woman, one flesh. That is not merely narrative. Jesus treats it as normative.
Now move forward.
In ~Exodus 20:14, “Thou shalt not commit adultery.” The command is absolute. It does not define adultery narrowly. The broader covenant ethic is sexual exclusivity within marriage.
Now to the crucial New Testament clarification.
Jesus directly addresses this in ~Matthew 19:4–6. He does not appeal to Mosaic case laws permitting polygamy. He appeals to creation: “Have ye not read, that he which made them at the beginning made them male and female… Wherefore they are no more twain, but one flesh.” He restores the Genesis design as binding.
More directly relevant is ~Matthew 19:9: “Whosoever shall put away his wife, except it be for fornication, and shall marry another, committeth adultery.”
Notice leasel, adultery is committed by a married man who marries another. The text does not say “if the second woman is married.” The act of taking another while still bound to the first is itself called adultery.
Also consider ~Mark 10:11–12: “Whosoever shall put away his wife, and marry another, committeth adultery against her.” The adultery is against his wife. That means the covenant breach itself constitutes adultery, even if the second woman is unmarried.
Paul reinforces this in ~Romans 7:2–3: “So then if, while her husband liveth, she be married to another man, she shall be called an adulteress.” The logic of covenant bond is central. The marriage tie remains binding while the spouse lives.
Now about polygamy in the Old Testament.
It is true that Scripture regulates polygamy. ~Exodus 21:10 instructs that if a man takes another wife, he must not diminish the first wife’s food, clothing, or marital rights. But regulation is not endorsement. The Old Testament also regulates divorce, slavery, and kingship abuses. Regulation often exists to restrain damage in a fallen society, not to express the creational ideal.
When Jesus interprets divorce in ~Matthew 19:8, He says Moses permitted it “because of the hardness of your hearts.” That principle applies broadly. Mosaic law accommodated human sinfulness. Christ restores the original design.
Now apply this to the present situation.
If the man is married and his wife is living, he is covenantally bound to her. To take another woman as a second wife under the New Covenant is not described as permissible. It is described as adultery. The New Testament standard for church leadership even requires being “the husband of one wife” (~1 Timothy 3:2). The trajectory of the New Testament is clearly monogamous.
Wanting to become a second wife does not make you manipulative. It makes you emotionally invested. That is human. But Scripture’s standard is not shaped by desire.
Definitive proof?
Mark 10:11.
Matthew 19:9.
Romans 7:3.
All explicitly treat remarriage while a spouse lives as adultery.
What should you do next?
Not formalize a covenant built on the breach of another covenant. That path compounds harm: to the wife, to the man, to yourself, and spiritually to all involved.
The hard truth is this: repentance and separation are biblically safer than attempting to sanctify a fractured situation.
This is about honoring covenant faithfulness. Scripture consistently places protection of the existing marriage bond above the legitimization of a new attachment.
Was this helpful sister? Far be it from me to make you feel “uncomfortable” in our community, you are safe here.
Johann.