Seems to me (as a layman -- limited knowledge, but learning...) that in the one extreme, 'God loves us and forgives us' as the alpha and omega of all that matters (and everything else is insignificant) is the ticket to unity.
In the other extreme, 'unless everything is exactly the way I think it should be, then there must be division' is a requirement of orthodoxy.
Seems to me that most "theological liberals" are in the former camp. And such a church organization is thoroughly unacceptable to theological conservatives, and would cause them to leave. But I don't perceive any theological conservatives to insist on having everything their own way. If they were, then I presume they'd be "free" Lutherans.
For the rest of us, I presume it boils down to identifying what the non-negotiables are -- those things which, if accepted, would leave those who objected to it, feeling and believing that they were violating their relationship with God, and violating the integrity of their own beliefs.
The homosex issue is obviously a non-negotiable -- for both sides: revisionists can't live without it, and traditionalists can't live with it. It is a complete, total, 100%, permanent impasse. And the longer it continues in the same church body, the more it's going to damage everyone. This 'family' isn't functional. It's a constant state of war. It's miserable for everyone.
Differences and diversity are indeed good, makes us richer for it, leads to learning and growth, etc. -- but only to a point. Beyond that point, there isn't enough common ground to be able to relate to each other.