Polygamy in the Old Testament and is it OK for Christians?

I may be able to help you out. I wrote a book on ancient Jewish marriage practices in today’s culture. There are two types of covenants in the bible. Contract law calls them either unilateral (one sided) or bilateral (two or more sided). We refer to them as conditional and unconditional covenants. In contract law, unilateral contracts are a “promise for performance” agreement. That means, after the offeree performs, the offeror’s promise becomes unconditional. Example is like a sign for a lost pet. The offeree (person looking for the pet) is not obligated to look or find the pet. The only person obligated is the person who promised a reward for their missing dog. This is not a contract until the offeree finds the dog and returns it to its owner (offeror). After the offeree performs, the offeror is bound by promise. There is nothing the offeree can do to break (or breach) their agreement. They have already performed for the promise. The only promise that remains is that of the offeree. Same with unilateral, marriage covenants. In the Old Testament, a man left his mother and father to find a wife for himself. The young woman stayed at home under her father’s rule (Number 30:16). The man (usually established and older) would see a young girl and ask who her father was (Genesis). The man would go to the woman’s father and ask what the bride price is? The girl’s father and the young man would enter into a bilateral agreement together for the young girl. She would usually not have a say in the betrothal. After the transaction, the woman was bound to the man by promise. Traditionally, the young girl was offered a cup of wine form the man (older and established). If she accepted the cup of wine (called the cup of acceptance) she became his wife by covenant. She only had to perform (consummation) as the final expression of her performance for the marriage. Since the man “acquired” the woman by the bride price, she became his possession (according to Jewish law). Therefore, sleeping with another man’s wife (or betrothed wife) was committing adultery and it was sinning against her husband. However, if the woman was raped in the country (where no one could save her) only the man was to die. The woman did not so a sin worthy of death. And if a man slept with an unmarried and unbetrothed woman (both willing), he had to offer his hand in marriage to the father (Exodus 22:16-17). However, the father could refuse but still require the bride price. Same with a man who raped the unbetrothed woman. He had to pay double bride price and could not divorce her all the days of his life (even if she was found with uncleanness according to the Law of Moses Deut. 24:1). The woman could not refuse the marriage after her father accepted the bride price, since he had authority over her. Submission comes from Gen. 3:16. The husband was given “rule” over his wife. Submission is a volunteer type of obedience. Headship is a way to rule over your wife that doesn’t “lord” over her. Submission just means to obey. She is under his rule. That is why, although the marriage covenants were unilateral, the woman could not marry another man (Romans 7:1-2). Since the man was not under the law of his wife, he was able to marry in polygamy.