I don't quite understand the phrasing of your response. Can you restate your point? Yes, societal upheaval will result by the missionary encouraging divorce. Never in the Bible is polygamy explicitly said to be sin, but God is said to hate divorce. Therefore, getting back to the ideal of one-husband-one-wife monogamy can occur in the 2nd generation to prevent family disintegration, the instantaneous making of formerly legitimate children into illegitimate bastards, and the reduction of former wives into second-class citizens (on the level of concubines instead of honorable wives) without a husband to provide for them. This method of letting polygamy die a natural death in the 2nd generation is the better method at ending polygamy than to suddenly end it and create many sudden further social problems. In II Samuel 12 Nathan the Prophet says that God would have given David many more wives, "And if that had been too little, I also would have given you much more! Why have you despised the commandment of the LORD, to do evil in His sight? You have killed Uriah the Hittite with the sword; you have taken his wife to be your wife.." Nathan calls David's adultery evil but says God would have granted David many more wives if only he did not do this sin of adultery. Therefore, we can prove that adultery is far worse than polygamy and that polygamy is not merely contractualized adultery, as some claim, but that it is true marriage. Also, we can see that adultery is not an awful abomination as, say homosexuality is, by the fact that God would not have offered something that heinously evil to David. The wives of the former king became his, and God had so richly granted so much wealth, and so many cattle, and so many wives to David that David's sin of taking what was not his was even worse because of it. In Ezekial 23 and Jeremiah 3 God portrays himself as a polygamist by way of illustration to show the unfaithfulness of his two kingdoms. We cannot fathom that God would portray himself as a homosexual or an adulterer, and yet God paints himself as married to two daughters of the same mother. Eze 23:1 The Word of Jehovah came again to me, Eze 23:2 Son of man, there were two women, the daughters of one mother. ...And they were Mine, and they bore sons and daughters. Eze 23:36-37 And Jehovah said to me: Son of man, will you judge Oholah and Oholibah, and declare to them their abominations, that they have committed adultery, Foreign sins always appear as more sinful than familiar sins. I would argue that Western promiscuity and adultery and divorce are worse sins than the polygamy of the Patriarchs. We read the OT and we marvel that these polygamist patriarchs could be God's people....but they, in turn, would marvel that sex-saturated modern Westerners who engage in sexual encounters freely with people who are not one of their many wives could be saved. We are at the stage in Western history where a return to the polygamy of the Patriarchs would be a moral improvement.