assuming that you actually follow the teachings of Christ, who not only NEVER opposed or spoke against polygamyThe is the same reasoning used by those who advocate sodomy - that since Jesus never specifically condemned it by name in the Gospels, it is somehow permitted.
Every time Jesus discussed marriage, He discussed it assuming that a marriage exists between one man and one woman.
and also states that Jewish law is not replaced but fulfilled
There is nothing in Jewish law that legislates polygamy excpet for the interesting provision of levirate marriage - which was not compulsory nor even encessary polygamous.
Are Christians required to live by the laws of levirate marriage?
but actually uses the parable of 10 Virgins in a polygamist marriage
The parable has nothing to do with polygamy whatever.
Sodomy is a practice of homosexuality and as such is banded in the law.
Incorrect about Jesus never discussing marriage as a polygamist marriage... again the parable of the 10 virgins. And while the MEANING of the parable has nothing to do with a polygamist marriage, any person who has read the original Greek and has studied the marriage customs of the 1st Century Jewish traditions would know that what is being described is a marriage. The fact that 5 of the 10 were married to a man that could support 10 wives provides added cultural emphasis that we do not understand. This emphasis shows how much more foolish the 5 that did not make it to the wedding.
While levitate marriage was not compulsory, it is obvious that it was EXPECTED under the law. Ask yourself this. What would happen if the brother did not marry? And while not necessarily polygamist, there is NOTHING in the law that prohibits it from being polygamist.
But by all means, do not take my word for it....or anyone else's. Study the texts for yourself, read the original Greek. Translate each word and explore the alternative meanings. You will find that the milk toast religion that is spoon feed out of most churches today is different from what is written in the original texts.