Unity is at times more important than truth. Paul speaks of issues which have an answer, but unity is more important than the answer.
You see truth at all costs is not Christian. Truth has value and some truth is of great value, but all truth is not equally important.
It is often odd debating with atheists who seem to view that any point of Christianity they object to can sink all of Christianity.
I do see the need to defend the whole faith, but the error in the atheist's approach is that he assumes that Christianity does not have a core and a periphery.
The reality is the Christian faith has an order of beliefs which is important. Not everything is worth dividing over in Christianity.
Some things are worth a good long discussion over but not worth dividing over. Some points are so minor they are not worth discussing if it would bring tension among brothers.