The bible has a certain broadness to Christian unity that the contemporary church does not have. In another sense the bible is far narrower on certain issues than the contemporary church.
The difference is that the bible constantly distinguishes between what is essential and what may be differed upon. Many of the non-negotiables center around the nature of God and the nature of God's work in the world.
These are the sort of issues that the contemporary church at time disparages as "theology which divides." It is in a sense a complaint about the over division in the church which already exists. Therefore we should not divide over theological issues.
What is missed is theological issues over the nature of God, and the nature of the Gospel are what the church should be concerned over.
In the bible there is a large sphere of non-essentials. Many of the divisions in the contemporary church are over non-essentials which churches should not divide over.
Often the non-essential issues are over things like order of worship, elements of worship, or music played. There are elements of these things which are important but often the importance in the current day is magnified past what is reasonable.
Often there becomes an advanced theology behind order of worship or the elements of worship or the type of music played. It often becomes so involved that the theological extensions are many stages removed conceptually from the bible by logical argumentation.
In a sense the contemporary church of all shapes and forms has developed a massive set of extra-biblical theology of how worship should look and sounds that it frequently takes more seriously than questions related the the gospel and nature of God.
Often the issue in the church is that it is majoring in minors. It is greatly concerned with getting things right which make little difference and there is little time left to make sure that the really important things are getting done. I think the issue is that we are often trying to market the gospel.
It is as if the gospel is not the power by which the world is overcome. We rather act often as if we need to package the gospel to somehow get people to get past the gospel.
It is true the gospel is difficult. But we do not help ourselves much by trying to focus on marketing the gospel at the expense of constantly proclaiming the gospel.