We should show sympathy for the Google impaired, rather than curtly telling them JFGI or JFBI:

https://www.google.ca/#q=christianity+multiple+wives

https://en.wikipedia.org/wiki/Polygamy_in_Christianity

http://www.sacred-texts.com/wmn/wcs/wcs09.htm

Aren't Mormons a branch of the Xer superstion?

Early Christians rejected marriage, calling it a corrupt Pagan custom. Monogamy was a Roman practice. Jews at the time of Jesus and later practiced plural marriage, despite Roman attempts to make Polygamy illegal.

The story of Hagar / Hājar in the Old Testament was the inspiration for the "Handmaiden" concept in this story, so it seems odd to claim that there is no correlation with Christianity, particularly since some Christians have practised Polygamy. 

Multiple wives are common in the Old Testament. 

According to the Bible "Righteous" Lot got both of his daughter's pregnant after his wife was turned into a Pillar of Salt (happens every day that, don't get God mad at you -).