Polygyny in Christianity
Note: Polygyny is a word that means having multiple wives. This practice is more commonly known as "polygamy", which means having multiple marriages. Technically, polygamy could refer to both polygyny and also polyandry, which is having multiple husbands. To avoid confusion, I use the term "polygyny"
Islam is a religion famous for its allowal of polygyny. Some people have gone so far as to identify polygyny as a specifically Muslim practice. This is wrong. In fact, polygyny is mentioned in the Bible! It was practiced by Abraham, Jacob, Moses, David, and Solomon, among others. It is specifically legislated for (Deuteronomy 21:18-17). Jesus mentions a wedding of a man with ten women without any condemnation (Gospel of Matthew 25:1-13 - read it!) while Paul places restrictions on polygyny only for priests and bishops (see for example 1 Timothy 3:12).
The famous Christian thinker Augustine of Hippo (354-430 CE) commented that polygyny had "recently" been banned among Christians since it was not a Roman custom and Christianity was now to be the official religion of the Roman Empire. A later Christian thinker and reformer, Martin Luther (1483-1546), advocated for polygyny on the grounds that what was lawful in the Bible should be acceptable to Christians.
A growing number of Christians today are calling for a return to the religion established by the Bible, which includes polygyny. Here are some webpages about this:
Bringing Christian Polygamy to the Churches
Christian Polygamy: Marriage Authorized By God
From A Woman's Place: The Case for Polygamy
Polygamy Reconsidered: African Plural Marriage and the Christian Churches
Polygamy: The Ultimate Feminist Lifestyle
The Christian Polygamy Page