Why is it that the Lord never forbade polygamy?
Actually, he did in Genesis 1:27 and 2:24. In Matthew 19:2-9, Jesus cited those texts of Scripture to prove to the Pharisees that divorce-for-any-reason is Biblically not permissible. The way he framed that argument shows that these texts from Genesis also forbid polygamy.
Consider Mathew 19:2-9:
Pharisees came to him, testing him, and saying, "Is it lawful for a man to divorce his wife for any reason?" He answered, "Haven't you read that he who made them from the beginning 'made them male and female' [Genesis 1:27], and said, 'For this cause a man shall leave his father and mother, and shall join to his wife; and the two shall become one flesh' [Genesis 2:24]? So that they are no more two, but one flesh. What therefore God has joined together, don't let man tear apart." They asked him, "Why then did Moses command us to give her a bill of divorce, and divorce her?" He said to them, "Moses, because of the hardness of your hearts, allowed you to divorce your wives, but from the beginning it has not been so. I tell you that whoever divorces his wife, except for sexual immorality, and marries another, commits adultery; and he who marries her when she is divorced commits adultery."
Jesus establishes from Genesis 1:27 and 2:24 that marriage makes two persons into one flesh. Unless married persons have divorced lawfully (because one spouse is guilty of sexual infidelity as in Matthew 5:32 or one spouse is an unbeliever guilty of willful desertion that cannot be remedied as in 1 Cor. 7:13-15), which frees the innocent spouse to remarry, subsequent marriage of either to a third party is adultery against the first spouse. By the same reasoning, marriage to more than one wife (or husband) would also be adultery.
In 1 Corinthians 6:12-7:40, the Apostle Paul deals with questions surrounding "fornication" (sexual infidelity), marriage, and divorce on the basis of the same understanding of the one-flesh nature of marriage which Jesus sets forth in Matthew 5:32 and Matthew 19:2-89. On the basis of such Scripture, the Westminster Confession of Faith has this to say in Chapter 24, "Of Marriage and Divorce:
1. Marriage is to be between one man and one woman: neither is it lawful for any man to have more than one wife, nor for any woman to have more than one husband, at the same time....
3. It is lawful for all sorts of people to marry, who are able with judgment to give their consent. Yet it is the duty of Christians to marry only in the Lord....
6. Although the corruption of man be such as is apt to study arguments unduly to put asunder those whom God hath joined together in marriage: yet, nothing but adultery, or such willful desertion as can no way be remedied by the church, or civil magistrate, is cause sufficient of dissolving the bond of marriage....
I realize this may have raised new questions for you regarding marriage and divorce, and my reasoning may not be as clear as I hope. Do feel free to follow up with me. In the meantime, I pray the Spirit of Christ will lead you into a full understanding of all things taught in the Word of God.
"Questions and Answers" is a weekly feature of the OPC website. The answers come from individual ministers in the Orthodox Presbyterian Church expressing their own convictions and do not necessarily represent an "official" position of the Church, especially in areas where the Standards of the Church (the Scriptures and the Westminster Confession of Faith and Catechisms) are silent.
The questions come from individuals like yourself. If you have questions about biblical and theological matters, you are invited to send them by e-mail by using the "Pose a Question" link on the OPC home page or by clicking here.
At least one new question is posted each week, so there should always be something new here for you to read. (For those people who would like to look at previous questions and answers, they will continue to be available as well.)
The purpose of the OPC website's "Questions and Answers" is to respond to biblical and theological questions. Matters of church discipline, disputes, or debates go beyond the scope of our work. We recommend that you present your concerns in these areas to the appropriate judicatory. In most cases this will be to a local pastor, elder, or session. We do not want the website to replace personal involvement in, or commitment to, the local, visible church.
While we will respond to every serious questioner, we are not bound to give a substantive answer to every question, should we deem the question to be beyond the scope of our purpose or our own ability to answer.
You will receive an answer by e-mail. Please be patient as many of our respondents are busy pastors. The response to your question may take up to two (2) weeks. Some of the questions submitted will be chosen to be posted here, along with the corresponding answers.
Note that the "Questions and Answers" posted on the site have been editedall personal references are removed, Scripture references or from some source may be added, and sometimes portions are expandedto make the questions and answers more useful to a larger audience.