What an interesting thread, I'm glad I stumbled on it. As a believer myself, I find any open dialogue about one's faith, or lack thereof, to be useful, if it's sincere and not just a platform to vent.
For me, way before you can get to any thoughtful conclusions about the intersection of christianity and poly, you have to be clear about where you're starting. There are a lot of things that are represented as christianity, but in fact are not.
To understand what anyone says on this topic you really have to understand the foundations of their beliefs because there are so many places that understanding can diverge. Let me pose just a couple of them.
For me, the place to start, the foundation of all beliefs is whether you accept that there are absolutes or not. Is there truth that's always truth, no matter the context, time, place history, culture, etc? Or is everything relative?
IMHO, if you hold to the former - there are absolutes, then you're on the path from which christianity rises. If you hold the latter, then no matter where you go from there, you will never get to christianity.
From there, there are a whole series of questions to determine where you're heading. For example:
- Is there a god? One and only god?
- What is god?
- Is the bible an accurate representation of the mind of god?
- If there is a god, is he powerful enough to ensure we get a clear picture of him in scripture?
- If there is one true god who is lord and creator of all, and the bible reflects his heart and mind accurately, what does he expect of me?
- Is jesus god?
- Is there sin? What is sin?
And at this point you still have a long long way to go to even get close to how christianity and poly fit together.
Everyone has an opinion and so far is free to express it. But to say either that God is OK with poly, or that a poly lifestyle is sin, is almost impossible to interpret unless you've taken me down that whole path.
As a few folks have rightly pointed out, anyone can pluck a half dozen verses from scripture and craft an argument for or against almost anything. If that's true, then I'd say either you have to discard the whole thing or look at scripture with an end-to-end perspective. Of course, this completely depends on your perspective of what scripture is. :>)
Let's keep the conversation going.