Limited Tolerance

Over at T&S a discussion about the legalization of polygamy was closed after some of the participants got too heated. I’m not asking to continue that discussion here, but I do think it raises a central issue–how much diversity can and should the church tolerate?

What issues/practices/doctrines can we hold differing “righteous” positions on; and which require complete uniformity? How do describe the interplay between culture and gospel norms? Why does it seem that we are more comfortable with gospel norms varying through time, rather than varying by location? We can consent to the practice of polygamy in the OT or in the 19th century, but why not contemporary Africa?