The greatest theological question

Here's just a few things I remember hearing (and seeing) believers quarrel, fight and yes ... change churches about:

-Was the earth actually created in 6 literal days?
-How old is the earth?
-Should women be allowed to wear pants to church?
-Should women be allowed to be deacons?
-Can a divorced man preach from the pulpit?
-Can a believer lose his or her salvation?
-Does the Bible teach the doctrine of a Trinity?
-Exactly what is "the age of accountability?"
-Should clapping be allowed in church?
-Is Sunday really the Sabbath?
-Should stores be allowed to open on Sundays?
-Which translation of the Bible should we use?

But none of those comes close to being as theologically important as this:
How many people are getting saved when believers stay busy arguing, fighting and quarreling among themselves?