I think we need to be careful with unity in that it's easy to have to little of it and also easy to have too much of it.
If we have to little we fragment along ever-more trivial causes of division. You want two songs before prayers and I'd rather have three so we end up going our separate ways, which is silly.
If we have too much we potentially dilute our theology in the quest for unity with those who should never be a part of the body. As Paul asked, "what accord has Christ with Belial?" so fundamentally if people disagree on core doctrine there is unlikely to be unity unless someone compromises, and if core doctrine is subject to compromise it clearly isn't core doctrine at all.
A few weeks ago I was talking to a Christian guy who was concerned about some of the doctrinal issues I reject, raising the question that basically boiled down to "can't we just all get along?". I'd love to have said yes to that, but when the issues in question are things that I believe will build the kingdom of the beast while pretending to build the kingdom of Christ I don't see how I can tolerate it.