For all the non-muslims out reading this and not understanding the concept of polygeny let me explain. Lets consider human society to be made up of men and women in equal proportion (although women are statistically more but for arguments sake just assume the proportion is the same). Take the men's half and deduct from them those who die in wars, commit crimes and end up in jail, migrate abroad to find work, etc. From the remaining men, deduct those who are unable financially to support a family hence cannot marry. Then take the women's half who seldom fight in wars, goto jail, migrate alone, and who don't have to provide in order to marry. You will end up with an imbalance. So the question becomes, what do the women do who can't find a husband? Their misery is much greater than the jealousy a married woman feels when a husband marries again. This is why God allowed polygeny, not only in islam, but in all heavenly scriptures. Apply this concept to a country recovering from civil war, urban strife, poverty you name it, and you will find that for a man to support more than one wife is an alleviation for women in most of these cases. The question becomes, why has the christian church prohibited it, and how does the church answer societies facing severe hardships such as those aforementioned?