Thank you all for all of your comments.
I find really interesting (but valid) the level of concerns people have with the anticipated narrative perspective, and the potential for conflict. I didn't even think of that as an issue. I have used primarily Jewish sources, but Christian (and Muslim) scripture provide additional detail for the setting, and I have tried not to have anything offensive to any faith (although the plot has to deviate, as it is Ishmael and not Isaac who Abraham takes to Moriah to sacrifice in Islamic scripture). In the book, God exists, but generally at a distance (or later, in telling Abraham some specific things on a few specific instances), but there is no other religion except for practices that the characters invent. I guess some may find offense by the absence of certain religious elements that they expect, and there's bound to be some people who don't like any retelling of biblical stories, but Anita Diamant with The Red Tent and OSC's Women of Genesis series seemed to dodge huge controversy. I don't think of my narrative as being more provocative, but you never know. The natural implications of repopulating a world from three brothers and their wives, particularly when the commandment of God is to be fruitful and multiply, may be shocking to some, but only in terms of "I don't want to hear about it," not in terms of what had to have happened.
And for the most part I am telling a more modern-perspective story. Unlike the conventional narrative that in the bible, life was pretty much unchanged and God was everywhere, the text suggests the exact opposite. In seven generations the world moves from three couples to seventy nations, with cities, technology, and society evolving rapidly -- but God is mostly a memory from centuries earlier. What would they have thought about, particularly someone like Shem is lives an unnatural life centuries long, seeing all the change.
Anyhow, thanks again for the comments