The church is what?
I think part of our problem in Western culture is we've attached ourselves to that translation which renders the word "church" which we tend to associate with a building or denomination, or even a particular dogma.
The original word from the Greek is "ekklesia," which really translates more closely to "a gathering or assembly." The principal point is the "church" as Jesus referred to it is the people it consists of.
And there really can be only one ekklesia for Jesus followers. We may differ on points of doctrine, and how we may choose to worship, but it's all one, or should be, in my understanding.
Unfortunately, this also means the church, or ekklesia, is made up of people-- fallible, often irritating, dogmatic-- people. It's too easy for us to point at this church or that denomination and say "wrong, wrong, wrong," and confuse that with Jesus' ekklesia.
If we are genuinely trying to follow Jesus in his teaching of how to live our lives, and truly believe he is, in fact, God of all creation, then we're part of his ekklesia, regardless of whatever exterior trappings we associate ourselves with.
I think, in terms of the poly lifestyle, for genuine Jesus followers, you have to decide whether what Jesus taught supports or discourages it. And of course, you will have very different opinions on that. But that should not divide us.