I totally agree that "biblical" marriage is not found in the Bible. The prophets however were against polygamy, which carried over into the early church. And it is interesting that in Exodus 21, a slave wife who had no choice had rights to support, including sexual relations, or her owner-husband had to let her go. Its would seem that a wife who was not a slave could also divorce her husband—but only if he gave her the writ of divorce, a great obstacle.

Also, I think it is interesting to note that a high fertility rate was essential to staying afloat as a community, what with 50% of children dying by age 12, wars, famines, etc. I have argued in print that this underlies a lot of biblical strictures.

You might like this book, Dan: Colin Hamer, Marital Imagery in the Bible: An Exploration of Genesis 2: 24 and its Significance for the Understanding of New Testament Divorce and Remarriage Teaching (London: Apostolos Publishing Ltd., 2015). The author is an English Baptist.

Keep writing!